Resin composition and molded article

Abstract

This resin composition contains: a liquid crystal polymer (A) including at least one repeat structural unit selected from the group consisting of repeat structural units represented by formulae (I)-(IV); and a predetermined polyimide resin (B). This molded article contains said resin composition. (a, b, and c each represent an average number of repeat structural units.)

Description

[Technical Field]

[0001] The present invention relates to a resin composition and a molded article. [Background technology]

[0002] Liquid crystal polymers, which are thermoplastic resins, are known as organic materials having low dielectric constants and low dielectric loss tangents, and are used as materials for forming insulating layers of printed wiring boards (see, for example, Patent Documents 1 and 2). On the other hand, liquid crystal polymers have a high crystallization rate and a low elasticity when melted, which makes them difficult to handle during melt molding. Furthermore, because liquid crystal polymers are structurally hard and have low flexibility and toughness, improvements in their mechanical properties are also desired. Furthermore, in recent years, there has been an increasing demand for low-dielectric materials as components related to fifth-generation mobile communication systems (5G) and sixth-generation mobile communication systems (6G), and from the viewpoint of obtaining high electrical properties, organic materials having, for example, a low dielectric constant of 3.0 or less and a low dielectric loss tangent of 0.005 or less are required. However, it has been difficult to achieve both the above levels of low dielectric constant and low dielectric loss tangent using liquid crystal polymers alone. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-317953 [Patent Document 2] Japanese Patent Application Laid-Open No. 2011-216841 Summary of the Invention [Problem to be solved by the invention]

[0004] The object of the present invention is to provide a resin composition containing a liquid crystal polymer, which has excellent handleability when molten, is easy to melt-knead and extrude, and can achieve both a low dielectric constant and a low dielectric loss tangent, and a molded article containing the resin composition. [Means for solving the problem]

[0005] The present inventors have found that the above-mentioned problems can be solved by a resin composition containing a predetermined liquid crystal polymer and a crystalline thermoplastic polyimide resin in which specific different polyimide structural units are combined in a specific ratio. That is, the present invention relates to the following. [1] A resin composition comprising: a liquid crystal polymer (A) containing at least one repeating structural unit selected from the group consisting of repeating structural units represented by the following formulas (I) to (IV); and a polyimide resin (B) containing a repeating structural unit represented by the following formula (1) and a repeating structural unit represented by the following formula (2), wherein the content of the repeating structural unit of the formula (1) relative to the total of the repeating structural units of the formula (1) and the repeating structural units of the formula (2) is 20 to 70 mol %. [ka] (a, b, and c represent the average number of repeating units.) [ka] (R1 is a divalent group having 6 to 22 carbon atoms and containing at least one alicyclic hydrocarbon structure. R2 is a divalent chain aliphatic group having 5 to 16 carbon atoms. X1 and X2 are each independently a tetravalent group having 6 to 22 carbon atoms and containing at least one aromatic ring.) [2] A molded article comprising the resin composition described in [1] above. [Effects of the Invention]

[0006] The resin composition of the present invention contains a liquid crystal polymer, yet has excellent handleability when molten, is easy to melt-knead, and is extrudable, and can achieve both a low dielectric constant and a low dielectric loss tangent. The resin composition and molded articles containing the same can be extrusion-molded, and are expected to be used in applications requiring a low dielectric constant and a low dielectric loss tangent. For example, the resin composition can be used in components related to fifth-generation mobile communication systems (5G) and sixth-generation mobile communication systems (6G), as well as other electrical and electronic components, insulating films, and the like. DETAILED DESCRIPTION OF THE INVENTION

[0007] [Resin composition] The resin composition of the present invention is a resin composition containing a liquid crystal polymer (A) containing at least one repeating structural unit selected from the group consisting of repeating structural units represented by the following formulas (I) to (IV), and a polyimide resin (B) containing a repeating structural unit represented by the following formula (1) and a repeating structural unit represented by the following formula (2), wherein the content of the repeating structural unit of formula (1) relative to the total of the repeating structural units of formula (1) and (2) is 20 to 70 mol %. [ka] (a, b, and c represent the average number of repeating units.) [ka] (R1 is a divalent group having 6 to 22 carbon atoms and containing at least one alicyclic hydrocarbon structure. R2 is a divalent chain aliphatic group having 5 to 16 carbon atoms. X1 and X2 are each independently a tetravalent group having 6 to 22 carbon atoms and containing at least one aromatic ring.)

[0008] By having the above-mentioned configuration, the resin composition of the present invention contains a liquid crystal polymer, yet has excellent handling properties when molten, is easy to melt-knead and extrude, and is a resin composition that combines a low dielectric constant and a low dielectric tangent (for example, a low dielectric constant of 3.0 or less and a low dielectric tangent of 0.005 or less). The reason why the present invention provides the above-mentioned effects is not clear, but is thought to be as follows. The liquid crystal polymer (A) (hereinafter also referred to simply as "component (A)") and the polyimide resin (B) (hereinafter also referred to simply as "component (B)") are both crystalline thermoplastic resins, and it is believed that they can be alloyed by melt-kneading them. By including the predetermined repeating structural unit, the liquid crystal polymer (A) can be a polymer that exhibits optical anisotropy and can achieve a low dielectric loss tangent of, for example, 0.005 or less. Furthermore, by using the liquid crystal polymer (A) in combination with the polyimide resin (B), the crystallization temperature is increased, and as a result, it is thought that a resin composition that has appropriate elasticity even when melted at high temperatures (200°C or higher) and is easy to handle when melted can be obtained. Furthermore, it has been difficult to achieve a low dielectric constant of 3.0 or less using the liquid crystal polymer (A) alone. However, by using it in combination with the polyimide resin (B) having a specific structure, it has become possible to achieve both a low dielectric constant and a low dielectric loss tangent. Furthermore, it is believed that the increase in torque, resin temperature, and resin pressure during melt-kneading and extrusion can be suppressed compared to when the polyimide resin (B) is used alone.

[0009] <Liquid Crystal Polymer (A)> The liquid crystal polymer used in the present invention contains at least one repeating structural unit selected from the group consisting of repeating structural units represented by the following formulas (I) to (IV): By containing this repeating structural unit, the liquid crystal polymer (A) can be made into a liquid crystal polymer that exhibits optical anisotropy and can achieve a low dielectric loss tangent. [ka] (a, b, and c represent the average number of repeating units.)

[0010] The repeating unit represented by formula (I) is composed of units derived from polyethylene glycol, terephthalic acid, and 4-hydroxybenzoic acid. The repeating unit represented by formula (II) is composed of units derived from 4,4'-dihydroxybiphenyl, terephthalic acid, and 4-hydroxybenzoic acid. The repeating unit represented by formula (III) is composed of units derived from bis(4-hydroxyphenyl)propane (bisphenol A), terephthalic acid, and 4-hydroxybenzoic acid. The repeating unit represented by formula (IV) is composed of units derived from 6-hydroxy-2-naphthoic acid and 4-hydroxybenzoic acid. In the above formula, a, b, and c represent the average number of repeating structural units, and each may be a number of 1 or more.

[0011] The liquid crystal polymer (A) may contain at least one of the repeating structural units represented by formulas (I) to (IV), and may contain two or more of them. From the viewpoint of achieving a low dielectric constant and a low dielectric loss tangent, the liquid crystal polymer (A) more preferably contains the repeating structural unit represented by formula (IV). In the liquid crystal polymer (A), the total content of the repeating structural units represented by formulas (I) to (IV) is preferably 50% by mass or more, more preferably 60% by mass or more, even more preferably 70% by mass or more, and even more preferably 80% by mass or more, from the viewpoint of obtaining a resin composition with a low dielectric tangent, and may be 100% by mass.

[0012] The liquid crystal polymer (A) may contain any structural unit other than the structural units contained in the repeating structural units represented by formulas (I) to (IV), including structural units derived from one or more members selected from the group consisting of aromatic hydroxycarboxylic acids, aromatic dicarboxylic acids, aromatic diols, aromatic aminocarboxylic acids, aromatic hydroxyamines, aromatic diamines, aliphatic diols, and aliphatic dicarboxylic acids.

[0013] In the liquid crystal polymer (A) containing a repeating structural unit of any one of formulas (I) to (III), examples of the optional structural unit derived from an aromatic hydroxycarboxylic acid include structural units derived from 3-hydroxybenzoic acid, 2-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid, 5-hydroxy-2-naphthoic acid, 7-hydroxy-2-naphthoic acid, 3-hydroxy-2-naphthoic acid, 4'-hydroxyphenyl-4-benzoic acid, 3'-hydroxyphenyl-4-benzoic acid, and 4'-hydroxyphenyl-3-benzoic acid. In the liquid crystal polymer (A) containing a repeating structural unit of formula (IV), examples of the optional structural unit derived from an aromatic hydroxycarboxylic acid other than 6-hydroxy-2-naphthoic acid include structural units derived from 3-hydroxybenzoic acid, 2-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid, 5-hydroxy-2-naphthoic acid, 7-hydroxy-2-naphthoic acid, 3-hydroxy-2-naphthoic acid, 4'-hydroxyphenyl-4-benzoic acid, and 4'-hydroxyphenyl-3-benzoic acid. In the liquid crystal polymer (A) containing a repeating structural unit of formula (IV), examples of the optional structural unit derived from an aromatic hydroxycarboxylic acid other than 6-hydroxy-2-naphthoic acid are given.

[0014] In the liquid crystal polymer (A) containing a repeating structural unit of any one of formulas (I) to (III), examples of the optional structural unit derived from an aromatic dicarboxylic acid include structural units derived from isophthalic acid, 2,6-naphthalenedicarboxylic acid, 1,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 4,4'-dicarboxybiphenyl, 3,4'-dicarboxybiphenyl, 4,4''-dicarboxyterphenyl, ethylene glycol bis(4-carboxyphenyl)ether, bis(4-carboxyphenoxy)butane, bis(4-carboxyphenyl)ethane, ethylene glycol bis(3-carboxyphenyl)ether, and bis(3-carboxyphenyl)ethane. In the liquid crystal polymer (A) containing a repeating structural unit of formula (IV), in addition to the structural units derived from the aromatic dicarboxylic acids exemplified above, structural units derived from terephthalic acid can be mentioned.

[0015] In the liquid crystal polymer (A) containing a repeating structural unit of any one of formulas (I) to (III), examples of the optional structural unit derived from an aromatic diol include structural units derived from hydroquinone, resorcinol, 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 3,3'-dihydroxybiphenyl, 3,4'-dihydroxybiphenyl, 4,4'-dihydroxybiphenol ether, bis(4-hydroxyphenyl)ethane, and 2,2'-dihydroxybinaphthyl. In the liquid crystal polymer (A) containing a repeating structural unit of formula (IV), examples of the optional structural unit derived from an aromatic diol include structural units derived from 4,4'-dihydroxybiphenyl and bis(4-hydroxyphenyl)propane, in addition to the structural units derived from the aromatic diols listed above.

[0016] Examples of optional structural units derived from aromatic aminocarboxylic acids include structural units derived from 4-aminobenzoic acid, 3-aminobenzoic acid, and 6-amino-2-naphthoic acid. Examples of optional structural units derived from aromatic hydroxyamines include structural units derived from 4-aminophenol, N-methyl-4-aminophenol, 3-aminophenol, 3-methyl-4-aminophenol, 4-amino-1-naphthol, 4-amino-4'-hydroxybiphenyl, 4-amino-4'-hydroxybiphenyl ether, 4-amino-4'-hydroxybiphenylmethane, 4-amino-4'-hydroxybiphenyl sulfide, and 2,2'-diaminobinaphthyl. Examples of the optional structural unit derived from an aromatic diamine include structural units derived from 1,4-phenylenediamine, 1,3-phenylenediamine, 1,5-diaminonaphthalene, 2,6-diaminonaphthalene, and 1,8-diaminonaphthalene.

[0017] In addition, the hydrogen atoms on the aromatic rings of the above aromatic dicarboxylic acids, aromatic diols, aromatic aminocarboxylic acids, aromatic hydroxyamines, and aromatic diamines may be substituted with alkyl groups, alkoxy groups, or halogens.

[0018] Examples of the optional structural unit derived from an aliphatic diol include, in the liquid crystal polymer (A) containing the repeating structural unit of formula (I), structural units derived from propylene glycol, 1,4-butanediol, 1,6-hexanediol, etc. In the liquid crystal polymer (A) containing the repeating structural units of formulas (II) to (IV), in addition to the structural units derived from the aliphatic diols exemplified above, structural units derived from ethylene glycol can be mentioned. Examples of optional structural units derived from aliphatic dicarboxylic acids include structural units derived from oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, tetradecanedioic acid, fumaric acid, maleic acid, and hexahydroterephthalic acid.

[0019] The optional structural unit may contain one or more types. However, from the viewpoint of obtaining a resin composition with a low dielectric loss tangent, when the liquid crystal polymer (A) contains the optional structural unit, the content thereof in the liquid crystal polymer (A) is preferably 50% by mass or less, more preferably 40% by mass or less, even more preferably 30% by mass or less, and still more preferably 20% by mass or less.

[0020] The melting point of the liquid crystal polymer (A) is preferably 180° C. or higher, more preferably 200° C. or higher, and even more preferably 215° C. or higher, from the viewpoint of ease of melt-kneading and extrusion with the polyimide resin (B) described below, and from the viewpoint of the heat resistance of the resulting resin composition. The upper limit of the melting point of the liquid crystal polymer (A) is not particularly limited, but from the viewpoint of the moldability of the resulting resin composition, it is preferably 350° C. or lower, more preferably 330° C. or lower.

[0021] There are no particular limitations on the method for producing the liquid crystal polymer (A), and the liquid crystal polymer (A) can be produced by subjecting polymerizable monomers for forming the respective repeating structural units constituting the liquid crystal polymer (A) to condensation polymerization by a known method.

[0022] <Polyimide resin (B)> The polyimide resin (B) used in the present invention contains a repeating structural unit represented by the following formula (1) and a repeating structural unit represented by the following formula (2), and the content ratio of the repeating structural unit of the formula (1) to the total of the repeating structural units of the formula (1) and the repeating structural units of the formula (2) is 20 to 70 mol %. By containing both the liquid crystal polymer (A) and the polyimide resin (B), the resin composition of the present invention is excellent in handleability when melted, melt-kneadability, and extrudability, and can obtain a resin composition having a low dielectric constant and a low dielectric loss tangent. [ka] (R1 is a divalent group having 6 to 22 carbon atoms and containing at least one alicyclic hydrocarbon structure. R2 is a divalent chain aliphatic group having 5 to 16 carbon atoms. X1 and X2 are each independently a tetravalent group having 6 to 22 carbon atoms and containing at least one aromatic ring.)

[0023] The polyimide resin (B) used in the present invention is a thermoplastic resin, and is preferably in the form of powder or pellets. Thermoplastic polyimide resins are formed by molding a polyimide precursor such as polyamic acid and then closing the imide rings, and are distinguished from polyimide resins that do not have a glass transition temperature (Tg) or that decompose at a temperature lower than the glass transition temperature.

[0024] The repeating unit of formula (1) is described in detail below. R1 is a divalent group having 6 to 22 carbon atoms and containing at least one alicyclic hydrocarbon structure. Here, the alicyclic hydrocarbon structure means a ring derived from an alicyclic hydrocarbon compound, and the alicyclic hydrocarbon compound may be saturated or unsaturated, and may be monocyclic or polycyclic. Examples of the alicyclic hydrocarbon structure include, but are not limited to, cycloalkane rings such as cyclohexane rings, cycloalkene rings such as cyclohexene rings, bicycloalkane rings such as norbornane rings, and bicycloalkene rings such as norbornene rings. Among these, preferred are cycloalkane rings, more preferred are cycloalkane rings having 4 to 7 carbon atoms, and even more preferred are cyclohexane rings. R1 has 6 to 22 carbon atoms, and preferably 8 to 17 carbon atoms. R1 contains at least one alicyclic hydrocarbon structure, and preferably contains 1 to 3 alicyclic hydrocarbon structures.

[0025] R1 is preferably a divalent group represented by the following formula (R1-1) or (R1-2). [ka] (m 11 and m 12 are each independently an integer of 0 to 2, preferably 0 or 1. 13 ~m 15 are each independently an integer of 0 to 2, preferably 0 or 1.

[0026] R1 is particularly preferably a divalent group represented by the following formula (R1-3). [ka] In the divalent group represented by the above formula (R1-3), the positional relationship of the two methylene groups with respect to the cyclohexane ring may be either cis or trans, and the ratio of cis to trans may be any value.

[0027] X1 is a tetravalent group having 6 to 22 carbon atoms and containing at least one aromatic ring. The aromatic ring may be a single ring or a condensed ring, and examples thereof include a benzene ring, a naphthalene ring, an anthracene ring, and a tetracene ring, but are not limited to these. Among these, a benzene ring and a naphthalene ring are preferred, and a benzene ring is more preferred. X1 has 6 to 22 carbon atoms, and preferably 6 to 18 carbon atoms. X1 contains at least one aromatic ring, preferably 1 to 3.

[0028] X1 is preferably a tetravalent group represented by any one of the following formulae (X-1) to (X-4). [ka] (R 11 ~R 18 are each independently an alkyl group having 1 to 4 carbon atoms. 11 ~p 13 are each independently an integer of 0 to 2, preferably 0. 14 , p 15 , p 16 and p 18 are each independently an integer of 0 to 3, preferably 0. 17 is an integer of 0 to 4, preferably 0. 11 ~L 13 are each independently a single bond, an ether group, a carbonyl group, or an alkylene group having 1 to 4 carbon atoms. Since X1 is a tetravalent group having 6 to 22 carbon atoms and containing at least one aromatic ring, R 12 , R 13 , p 12 and p 13 is selected so that the number of carbon atoms in the tetravalent group represented by formula (X-2) falls within the range of 10 to 22. Similarly, L in formula (X-3) 11 , R 14 , R 15 , p 14 and p 15 is selected so that the number of carbon atoms of the tetravalent group represented by formula (X-3) is in the range of 12 to 22, and L in formula (X-4) 12 , L 13 , R 16 , R 17 , R 18 , p 16 , p 17 and p 18is selected so that the number of carbon atoms in the tetravalent group represented by formula (X-4) falls within the range of 18 to 22.

[0029] X1 is particularly preferably a tetravalent group represented by the following formula (X-5) or (X-6). [ka]

[0030] Next, the repeating unit of formula (2) will be described in detail below. R2 is a divalent chain aliphatic group having 5 to 16 carbon atoms, preferably 6 to 14 carbon atoms, more preferably 7 to 12 carbon atoms, and even more preferably 8 to 10 carbon atoms. Here, the chain aliphatic group means a group derived from a chain aliphatic compound, and the chain aliphatic compound may be saturated or unsaturated, linear or branched, and may contain a heteroatom such as an oxygen atom. R2 is preferably an alkylene group having 5 to 16 carbon atoms, more preferably an alkylene group having 6 to 14 carbon atoms, even more preferably an alkylene group having 7 to 12 carbon atoms, and of these, preferably an alkylene group having 8 to 10 carbon atoms. The alkylene group may be a linear alkylene group or a branched alkylene group, but is preferably a linear alkylene group. R2 is preferably at least one selected from the group consisting of an octamethylene group and a decamethylene group, and particularly preferably an octamethylene group.

[0031] Another preferred embodiment of R2 is a divalent chain aliphatic group containing an ether group and having 5 to 16 carbon atoms. The number of carbon atoms is preferably 6 to 14, more preferably 7 to 12, and even more preferably 8 to 10. Among these, preferred are divalent groups represented by the following formula (R2-1) or (R2-2). [ka] (m 21 and m 22are each independently an integer of 1 to 15, preferably 1 to 13, more preferably 1 to 11, and even more preferably 1 to 9. 23 ~m 25 are each independently an integer of 1 to 14, preferably 1 to 12, more preferably 1 to 10, and even more preferably 1 to 8. Since R2 is a divalent chain aliphatic group having 5 to 16 carbon atoms (preferably 6 to 14 carbon atoms, more preferably 7 to 12 carbon atoms, and even more preferably 8 to 10 carbon atoms), m in formula (R2-1) 21 and m 22 is selected so that the carbon number of the divalent group represented by formula (R2-1) is in the range of 5 to 16 (preferably 6 to 14 carbon atoms, more preferably 7 to 12 carbon atoms, and even more preferably 8 to 10 carbon atoms). That is, m 21 +m 22 is 5 to 16 (preferably 6 to 14, more preferably 7 to 12, and even more preferably 8 to 10). Similarly, m in formula (R2-2) 23 ~m 25 is selected so that the carbon number of the divalent group represented by formula (R2-2) is in the range of 5 to 16 (preferably 6 to 14 carbon atoms, more preferably 7 to 12 carbon atoms, and even more preferably 8 to 10 carbon atoms). That is, m 23 +m 24 +m 25 has 5 to 16 carbon atoms (preferably 6 to 14 carbon atoms, more preferably 7 to 12 carbon atoms, and even more preferably 8 to 10 carbon atoms).

[0032] X2 is defined in the same manner as X1 in formula (1), and the preferred embodiments are also the same.

[0033] The content ratio of the repeating structural unit of formula (1) to the total of the repeating structural unit of formula (1) and the repeating structural unit of formula (2) is 20 to 70 mol %. When the content ratio of the repeating structural unit of formula (1) is within this range, it becomes possible to sufficiently crystallize the polyimide resin even in a general injection molding cycle. If the content ratio is less than 20 mol %, molding processability decreases, and if it exceeds 70 mol %, crystallinity decreases, resulting in a decrease in heat resistance. The content ratio of the repeating structural unit of formula (1) relative to the total of the repeating structural units of formula (1) and formula (2) is preferably 65 mol % or less, more preferably 60 mol % or less, and even more preferably 50 mol % or less, from the viewpoint of achieving high crystallinity. In particular, the content ratio of the repeating structural unit of formula (1) to the total of the repeating structural units of formula (1) and formula (2) is preferably 20 mol % or more and less than 40 mol %. Within this range, the crystallinity of the polyimide resin (B) is increased, and a resin composition with even better heat resistance can be obtained. From the viewpoint of moldability, the content ratio is preferably 25 mol% or more, more preferably 30 mol% or more, and even more preferably 32 mol% or more, and from the viewpoint of achieving high crystallinity, it is even more preferably 35 mol% or less.

[0034] The total content ratio of the repeating structural units of formula (1) and the repeating structural units of formula (2) relative to all repeating structural units constituting polyimide resin (B) is preferably 50 to 100 mol %, more preferably 75 to 100 mol %, even more preferably 80 to 100 mol %, and still more preferably 85 to 100 mol %.

[0035] The polyimide resin (B) may further contain a repeating structural unit of the following formula (3). In this case, the content ratio of the repeating structural unit of formula (3) to the total of the repeating structural units of formula (1) and formula (2) is preferably 25 mol % or less. On the other hand, there is no particular lower limit, and it is sufficient that it is more than 0 mol %. From the viewpoint of improving heat resistance, the content ratio is preferably 5 mol % or more, more preferably 10 mol % or more, while from the viewpoint of maintaining crystallinity, the content ratio is preferably 20 mol % or less, more preferably 15 mol % or less. [ka] (R3 is a divalent group having 6 to 22 carbon atoms and containing at least one aromatic ring. X3 is a tetravalent group having 6 to 22 carbon atoms and containing at least one aromatic ring.)

[0036] R3 is a divalent group having 6 to 22 carbon atoms and containing at least one aromatic ring. The aromatic ring may be a single ring or a condensed ring, and examples thereof include a benzene ring, a naphthalene ring, an anthracene ring, and a tetracene ring, but are not limited to these. Among these, a benzene ring and a naphthalene ring are preferred, and a benzene ring is more preferred. R3 has 6 to 22 carbon atoms, and preferably 6 to 18 carbon atoms. R3 contains at least one aromatic ring, preferably 1 to 3. The aromatic ring may have a monovalent or divalent electron-withdrawing group bonded thereto. Examples of the monovalent electron-withdrawing group include a nitro group, a cyano group, a p-toluenesulfonyl group, halogen, a halogenated alkyl group, a phenyl group, and an acyl group. Examples of the divalent electron-withdrawing group include a fluorinated alkylene group (e.g., -C(CF3)2-, -(CF2) p In addition to halogenated alkylene groups such as - (where p is an integer of 1 to 10), examples include -CO-, -SO2-, -SO-, -CONH-, -COO-, and the like.

[0037] R3 is preferably a divalent group represented by the following formula (R3-1) or (R3-2). [ka] (m 31 and m 32 are each independently an integer of 0 to 2, preferably 0 or 1. 33 and m 34 are each independently an integer of 0 to 2, preferably 0 or 1. 21 , R 22 , and R 23 are each independently an alkyl group having 1 to 4 carbon atoms, an alkenyl group having 2 to 4 carbon atoms, or an alkynyl group having 2 to 4 carbon atoms. 21 , p 22 and p 23 is an integer of 0 to 4, preferably 0. 21is a single bond, an ether group, a carbonyl group, or an alkylene group having 1 to 4 carbon atoms. Since R3 is a divalent group having 6 to 22 carbon atoms and containing at least one aromatic ring, m in formula (R3-1) 31 , m 32 , R 21 and p 21 is selected so that the divalent group represented by formula (R3-1) has 6 to 22 carbon atoms. Similarly, L in formula (R3-2) 21 , m 33 , m 34 , R 22 , R 23 , p 22 and p 23 is selected so that the divalent group represented by formula (R3-2) has 12 to 22 carbon atoms.

[0038] X3 is defined in the same manner as X1 in formula (1), and the preferred embodiments are also the same.

[0039] The polyimide resin (B) may further contain a repeating structural unit represented by the following formula (4). [ka] (R4 is -SO2- or -Si(R x )(R y )O-containing divalent group, and R x and R y each independently represents a chain aliphatic group having 1 to 3 carbon atoms or a phenyl group. X4 is a tetravalent group having 6 to 22 carbon atoms and containing at least one aromatic ring. X4 is defined in the same manner as X1 in formula (1), and the preferred embodiments are also the same.

[0040] There are no particular restrictions on the terminal structure of the polyimide resin (B), but it is preferable that the polyimide resin (B) has a chain aliphatic group having 5 to 14 carbon atoms at the terminal. The chain aliphatic group may be saturated or unsaturated, and may be linear or branched. When the polyimide resin (B) has the specific group at its terminal, a resin composition excellent in heat aging resistance can be obtained. Examples of saturated chain aliphatic groups having 5 to 14 carbon atoms include an n-pentyl group, an n-hexyl group, an n-heptyl group, an n-octyl group, an n-nonyl group, an n-decyl group, an n-undecyl group, a lauryl group, an n-tridecyl group, an n-tetradecyl group, an isopentyl group, a neopentyl group, a 2-methylpentyl group, a 2-methylhexyl group, a 2-ethylpentyl group, a 3-ethylpentyl group, an isooctyl group, a 2-ethylhexyl group, a 3-ethylhexyl group, an isononyl group, a 2-ethyloctyl group, an isodecyl group, an isododecyl group, an isotridecyl group, and an isotetradecyl group. Examples of the unsaturated chain aliphatic group having 5 to 14 carbon atoms include a 1-pentenyl group, a 2-pentenyl group, a 1-hexenyl group, a 2-hexenyl group, a 1-heptenyl group, a 2-heptenyl group, a 1-octenyl group, a 2-octenyl group, a nonenyl group, a decenyl group, a dodecenyl group, a tridecenyl group, and a tetradecenyl group. Among these, the chain aliphatic group is preferably a saturated chain aliphatic group, and more preferably a saturated linear aliphatic group. From the viewpoint of obtaining heat aging resistance, the chain aliphatic group preferably has 6 or more carbon atoms, more preferably 7 or more carbon atoms, even more preferably 8 or more carbon atoms, and preferably 12 or less carbon atoms, more preferably 10 or less carbon atoms, even more preferably 9 or less carbon atoms. The chain aliphatic group may be of only one type, or of two or more types. The chain aliphatic group is particularly preferably at least one selected from the group consisting of an n-octyl group, an isooctyl group, a 2-ethylhexyl group, an n-nonyl group, an isononyl group, an n-decyl group, and an isodecyl group, further preferably at least one selected from the group consisting of an n-octyl group, an isooctyl group, a 2-ethylhexyl group, an n-nonyl group, and an isononyl group, and most preferably at least one selected from the group consisting of an n-octyl group, an isooctyl group, and a 2-ethylhexyl group. From the viewpoint of heat aging resistance, the polyimide resin (B) preferably has, at its terminals, only chain aliphatic groups having 5 to 14 carbon atoms in addition to terminal amino groups and terminal carboxy groups. When groups other than the above are present at its terminals, the content thereof is preferably 10 mol % or less, more preferably 5 mol % or less, relative to the chain aliphatic groups having 5 to 14 carbon atoms.

[0041] From the viewpoint of exhibiting excellent heat aging resistance, the content of the chain aliphatic groups having 5 to 14 carbon atoms in the polyimide resin (B) is preferably 0.01 mol % or more, more preferably 0.1 mol % or more, and even more preferably 0.2 mol % or more, based on 100 mol % of the total of all repeating units constituting the polyimide resin (B). Furthermore, in order to ensure a sufficient molecular weight and obtain good mechanical properties, the content of the chain aliphatic groups having 5 to 14 carbon atoms in the polyimide resin (B) is preferably 10 mol % or less, more preferably 6 mol % or less, even more preferably 3.5 mol % or less, still more preferably 2.0 mol % or less, and even more preferably 1.2 mol % or less, based on 100 mol % of the total of all repeating units constituting the polyimide resin (B). The content of the chain aliphatic group having 5 to 14 carbon atoms in the polyimide resin (B) can be determined by depolymerizing the polyimide resin (B).

[0042] The polyimide resin (B) preferably has a melting point of 360° C. or lower and a glass transition temperature of 150° C. or higher. From the viewpoint of heat resistance, the melting point of the polyimide resin (B) is more preferably 280° C. or higher, and even more preferably 290° C. or higher. From the viewpoint of achieving high moldability, the melting point is preferably 345° C. or lower, more preferably 340° C. or lower, and even more preferably 335° C. or lower. From the viewpoint of heat resistance, the glass transition temperature of the polyimide resin (B) is more preferably 160° C. or higher, and even more preferably 170° C. or higher. From the viewpoint of achieving high moldability, the glass transition temperature is preferably 250° C. or lower, more preferably 230° C. or lower, and even more preferably 200° C. or lower. The melting point and glass transition temperature of the polyimide resin (B) can both be measured by a differential scanning calorimeter. From the viewpoint of improving crystallinity, heat resistance, mechanical strength, and chemical resistance, the polyimide resin (B) preferably has a calorific value of 5.0 mJ / mg or more, more preferably 10.0 mJ / mg or more, and even more preferably 17.0 mJ / mg or more of the heat value of the exothermic crystallization peak observed when the polyimide resin is melted and then cooled at a temperature decreasing rate of 20°C / min, as measured by a differential scanning calorimeter. The upper limit of the exothermic value of crystallization is not particularly limited, but is usually 45.0 mJ / mg or less. The melting point, glass transition temperature and crystallization heat of the polyimide resin (B) can be specifically measured by the methods described in the examples.

[0043] The logarithmic viscosity of a 5% by mass solution of polyimide resin (B) in concentrated sulfuric acid at 30°C is preferably in the range of 0.2 to 2.0 dL / g, more preferably 0.3 to 1.8 dL / g. If the logarithmic viscosity is 0.2 dL / g or higher, sufficient mechanical strength can be obtained when the resulting resin composition is molded into a molded article, while if it is 2.0 dL / g or lower, moldability and handleability are improved. The logarithmic viscosity μ can be calculated from the following formula by measuring the flow times of concentrated sulfuric acid and the polyimide resin solution at 30°C using a Cannon-Fenske viscometer: μ=ln(ts / t0) / C t0: Time when concentrated sulfuric acid flows ts: Flow time of polyimide resin solution C: 0.5 (g / dL)

[0044] The weight average molecular weight Mw of the polyimide resin (B) is preferably in the range of 10,000 to 150,000, more preferably 15,000 to 100,000, even more preferably 20,000 to 80,000, still more preferably 30,000 to 70,000, and even more preferably 35,000 to 65,000. If the weight average molecular weight Mw of the polyimide resin (B) is 10,000 or more, the mechanical strength is good, and if it is 150,000 or less, the moldability is good. The weight average molecular weight Mw of the polyimide resin (B) can be measured by gel permeation chromatography (GPC) using polymethyl methacrylate (PMMA) as a standard sample.

[0045] (Method for producing polyimide resin (B)) The polyimide resin (B) can be produced by reacting a tetracarboxylic acid component with a diamine component, wherein the tetracarboxylic acid component contains a tetracarboxylic acid and / or a derivative thereof having at least one aromatic ring, and the diamine component contains a diamine having at least one alicyclic hydrocarbon structure and a chain aliphatic diamine.

[0046] The tetracarboxylic acid containing at least one aromatic ring is preferably a compound in which four carboxy groups are directly bonded to the aromatic ring, and may contain an alkyl group in the structure. The tetracarboxylic acid preferably has 6 to 26 carbon atoms. Examples of the tetracarboxylic acid include pyromellitic acid, 2,3,5,6-toluenetetracarboxylic acid, 3,3',4,4'-benzophenonetetracarboxylic acid, 3,3',4,4'-biphenyltetracarboxylic acid, and 1,4,5,8-naphthalenetetracarboxylic acid. Among these, pyromellitic acid is more preferred.

[0047] Examples of the derivative of tetracarboxylic acid containing at least one aromatic ring include anhydrides or alkyl esters of tetracarboxylic acid containing at least one aromatic ring. The tetracarboxylic acid derivative preferably has 6 to 38 carbon atoms. Examples of the anhydride of tetracarboxylic acid include pyromellitic acid monoanhydride, pyromellitic acid dianhydride, 2,3,5,6-toluenetetracarboxylic acid dianhydride, 3,3',4,4'-diphenylsulfonetetracarboxylic acid dianhydride, 3,3',4,4'-benzophenonetetracarboxylic acid dianhydride, 3,3',4,4'-biphenyltetracarboxylic acid dianhydride, and 1,4,5,8-naphthalenetetracarboxylic acid dianhydride. Examples of alkyl esters of tetracarboxylic acids include dimethyl pyromellitate, diethyl pyromellitate, dipropyl pyromellitate, diisopropyl pyromellitate, dimethyl 2,3,5,6-toluenetetracarboxylate, dimethyl 3,3',4,4'-diphenylsulfonetetracarboxylate, dimethyl 3,3',4,4'-benzophenonetetracarboxylate, dimethyl 3,3',4,4'-biphenyltetracarboxylate, dimethyl 1,4,5,8-naphthalenetetracarboxylate, etc. In the alkyl esters of the above tetracarboxylic acids, the alkyl group preferably has 1 to 3 carbon atoms.

[0048] As the tetracarboxylic acid and / or derivative thereof containing at least one aromatic ring, at least one compound selected from the above may be used alone, or two or more compounds may be used in combination.

[0049] The diamine containing at least one alicyclic hydrocarbon structure preferably has 6 to 22 carbon atoms, and examples thereof include 1,2-bis(aminomethyl)cyclohexane, 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, 1,2-cyclohexanediamine, 1,3-cyclohexanediamine, 1,4-cyclohexanediamine, 4,4'-diaminodicyclohexylmethane, 4,4'-methylenebis(2-methylcyclohexylamine), carvonediamine, limonenediamine, isophoronediamine, norbornanediamine, bis(aminomethyl)tricyclo[5.2.1.0]diamine, and bis(aminomethyl)tricyclo[5.2.1.0]diamine.2,6 ]decane, 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane, 4,4'-diaminodicyclohexylpropane, etc. are preferred. These compounds may be used alone, or two or more compounds selected from these may be used in combination. Of these, 1,3-bis(aminomethyl)cyclohexane is preferably used. Note that diamines containing an alicyclic hydrocarbon structure generally have structural isomers, but the ratio of cis / trans isomers is not limited.

[0050] The chain aliphatic diamine may be linear or branched, and preferably has 5 to 16 carbon atoms, more preferably 6 to 14, and even more preferably 7 to 12. When the chain portion has 5 to 16 carbon atoms, it may contain an ether bond therebetween. Preferred examples of the chain aliphatic diamine include 1,5-pentamethylenediamine, 2-methylpentane-1,5-diamine, 3-methylpentane-1,5-diamine, 1,6-hexamethylenediamine, 1,7-heptamethylenediamine, 1,8-octamethylenediamine, 1,9-nonamethylenediamine, 1,10-decamethylenediamine, 1,11-undecamethylenediamine, 1,12-dodecamethylenediamine, 1,13-tridecamethylenediamine, 1,14-tetradecamethylenediamine, 1,16-hexadecamethylenediamine, and 2,2'-(ethylenedioxy)bis(ethyleneamine). The chain aliphatic diamine may be used alone or in combination. Among these, chain aliphatic diamines having 8 to 10 carbon atoms are preferably used, and in particular, at least one selected from the group consisting of 1,8-octamethylenediamine and 1,10-decamethylenediamine is preferably used.

[0051] When producing the polyimide resin (B), the molar ratio of the amount of the diamine containing at least one alicyclic hydrocarbon structure charged to the total amount of the diamine containing at least one alicyclic hydrocarbon structure and the chain aliphatic diamine is preferably 20 to 70 mol %. This molar amount is preferably 25 mol % or more, more preferably 30 mol % or more, and even more preferably 32 mol % or more, and from the viewpoint of achieving high crystallinity, is preferably 60 mol % or less, more preferably 50 mol % or less, even more preferably less than 40 mol %, and even more preferably 35 mol % or less.

[0052] The diamine component may also contain a diamine containing at least one aromatic ring. The diamine containing at least one aromatic ring preferably has 6 to 22 carbon atoms, and examples thereof include ortho-xylylenediamine, meta-xylylenediamine, para-xylylenediamine, 1,2-diethynylbenzenediamine, 1,3-diethynylbenzenediamine, 1,4-diethynylbenzenediamine, 1,2-diaminobenzene, 1,3-diaminobenzene, 1,4-diaminobenzene, 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylmethane, α,α'-bis(4-aminophenyl)1,4-diisopropylbenzene, α,α'-bis(3-aminophenyl)-1,4-diisopropylbenzene, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,6-diaminonaphthalene, and 1,5-diaminonaphthalene.

[0053] In the above, the molar ratio of the amount of the diamine containing at least one aromatic ring to the total amount of the diamine containing at least one alicyclic hydrocarbon structure and the chain aliphatic diamine is preferably 25 mol% or less, while the lower limit is not particularly limited as long as it is greater than 0 mol%. From the viewpoint of improving heat resistance, the molar ratio is preferably 5 mol% or more, more preferably 10 mol% or more, while from the viewpoint of maintaining crystallinity, the molar ratio is preferably 20 mol% or less, more preferably 15 mol% or less. Moreover, from the viewpoint of reducing coloration of the polyimide resin, the molar ratio is preferably 12 mol % or less, more preferably 10 mol % or less, even more preferably 5 mol % or less, and still more preferably 0 mol %.

[0054] When producing the polyimide resin (B), the ratio of the amount of the tetracarboxylic acid component to the amount of the diamine component charged is preferably 0.9 to 1.1 moles of the diamine component per mole of the tetracarboxylic acid component.

[0055] When producing the polyimide resin (B), a terminal blocking agent may be mixed in addition to the tetracarboxylic acid component and the diamine component. The terminal blocking agent is preferably at least one selected from the group consisting of monoamines and dicarboxylic acids. The amount of the terminal blocking agent used may be any amount sufficient to introduce a desired number of terminal groups into the polyimide resin (B), and is preferably 0.0001 to 0.1 mol, more preferably 0.001 to 0.06 mol, even more preferably 0.002 to 0.035 mol, still more preferably 0.002 to 0.020 mol, and even more preferably 0.002 to 0.012 mol, per mol of the tetracarboxylic acid and / or its derivative. Among these, the terminal blocking agent is preferably a monoamine terminal blocking agent, and from the viewpoint of improving heat aging resistance by introducing the aforementioned chain aliphatic group having 5 to 14 carbon atoms into the terminal of the polyimide resin (B), a monoamine having a chain aliphatic group having 5 to 14 carbon atoms is more preferred, and a monoamine having a saturated linear aliphatic group having 5 to 14 carbon atoms is even more preferred. The end-capping agent is particularly preferably at least one selected from the group consisting of n-octylamine, isooctylamine, 2-ethylhexylamine, n-nonylamine, isononylamine, n-decylamine, and isodecylamine, further preferably at least one selected from the group consisting of n-octylamine, isooctylamine, 2-ethylhexylamine, n-nonylamine, and isononylamine, and most preferably at least one selected from the group consisting of n-octylamine, isooctylamine, and 2-ethylhexylamine.

[0056] As the polymerization method for producing the polyimide resin (B), a known polymerization method can be applied, and the method described in WO 2016 / 147996 can be used.

[0057] The mass ratio [(A) / (B)] of the liquid crystal polymer (A) to the polyimide resin (B) in the resin composition of the present invention is not particularly limited, and may be in the range of 0.1 / 99.9 to 99.9 / 0.1. From the viewpoint of obtaining good handling properties in the melt, moldability, and a low dielectric constant, it is preferable that the proportion of the polyimide resin (B) is high, and from the viewpoint of obtaining good melt-kneadability, extrudability, and a low dielectric tangent, it is preferable that the proportion of the liquid crystal polymer (A) is high. From the viewpoint of achieving a low dielectric constant and a low dielectric loss tangent, particularly from the viewpoint of obtaining a resin composition having a dielectric constant of 3.0 or less and a dielectric loss tangent of 0.005 or less, the mass ratio [(A) / (B)] in the resin composition of the present invention is preferably in the range of 0.1 / 99.9 to 70 / 30, more preferably 0.1 / 99.9 to 50 / 50, even more preferably 0.1 / 99.9 to 40 / 60, and still more preferably 0.1 / 99.9 to 30 / 70.

[0058] From the viewpoint of obtaining the effects of the present invention, the total content of the liquid crystal polymer (A) and the polyimide resin (B) in the resin composition of the present invention is preferably 30% by mass or more, more preferably 40% by mass or more, even more preferably 50% by mass or more, still more preferably 65% ​​by mass or more, still more preferably 70% by mass or more, still more preferably 80% by mass or more, and still more preferably 90% by mass or more, with the upper limit being 100% by mass.

[0059] (reinforced fiber) The resin composition of the present invention may further contain reinforcing fibers in order to improve the mechanical strength, heat resistance, etc. of the resulting resin composition and molded article. Examples of reinforcing fibers include glass fibers, carbon fibers, aramid fibers, boron fibers, and metal fibers. One type of reinforcing fiber may be used alone, or two or more types may be used in combination.

[0060] There are no particular restrictions on the form of the reinforcing fibers, and either short fibers or continuous fibers can be used depending on the form of the resin composition and molded article to be obtained, or both may be used in combination. The form of the resin composition will be described later, but for example, when the resin composition of the present invention is in the form of pellets, the reinforcing fibers are preferably short fibers from the viewpoint of extrudability, etc. The resin composition may also be in the form of a prepreg in which reinforcing fibers are impregnated with a mixture containing the liquid crystal polymer (A) and the polyimide resin (B), and in this case, the reinforcing fibers are preferably continuous fibers.

[0061] When the reinforcing fibers are short fibers, the average fiber length is preferably 0.2 mm or more, more preferably 0.5 mm or more, and even more preferably 2 mm or more from the viewpoints of strength and handleability, and is preferably 25 mm or less, more preferably 15 mm or less, and even more preferably less than 10 mm from the viewpoints of extrusion moldability, etc. When the reinforcing fibers are continuous fibers, various forms can be mentioned, such as monofilaments or multifilaments simply arranged in one direction or so as to cross each other alternately, fabrics such as knitted or woven fabrics, nonwoven fabrics, mats, etc. Among these, the forms of monofilaments, fabrics, nonwoven fabrics, and mats are preferred, and the form of fabrics is more preferred. When the reinforcing fibers are continuous fibers, their fineness is preferably 20 to 4,500 tex, more preferably 50 to 4,000 tex. A fineness within this range facilitates impregnation with the resin component, and the resulting molded article has excellent elastic modulus and strength. The fineness can be determined by calculating the weight of continuous fibers of any length and converting it into the weight per 1,000 m.

[0062] The average fiber diameter of the reinforcing fibers is preferably 1 to 100 μm, more preferably 3 to 50 μm, and even more preferably 4 to 20 μm. When the average fiber diameter is within this range, processing is easy and the resulting molded article has excellent elastic modulus and strength. The average fiber length and average fiber diameter of the reinforcing fibers (short fibers) can be determined by randomly selecting 50 or more fibers, observing and measuring them using a scanning electron microscope (SEM) or the like, and calculating the number average.

[0063] Among the reinforcing fibers, at least one selected from the group consisting of glass fiber and carbon fiber is preferred from the viewpoint of improving mechanical strength, and carbon fiber is more preferred from the viewpoint of improving mechanical strength and lightweight properties. Examples of carbon fibers include polyacrylonitrile-based carbon fibers and pitch-based carbon fibers. The number of filaments in the carbon fiber is usually in the range of 500 to 100,000, preferably 5,000 to 80,000, and more preferably 10,000 to 70,000.

[0064] In order to improve the wettability and interfacial adhesion between the liquid crystal polymer (A) and the polyimide resin (B), the carbon fiber is preferably surface-treated with a surface treatment agent. The surface treatment agent includes a sizing agent and a sizing agent. Examples of surface treatment agents include epoxy-based materials, urethane-based materials, acrylic-based materials, polyamide-based materials, polyimide-based materials, polyester-based materials, vinyl ester-based materials, polyolefin-based materials, and polyether-based materials, and one or more of these can be used in combination. From the viewpoint of obtaining higher mechanical properties, epoxy-based materials or polyimide-based materials are preferred as surface treatment agents.

[0065] Commercially available carbon fibers (short fibers) can also be used. Examples of commercially available carbon fibers (short fibers) include the chopped fiber "CFUW", "CFEPP", "CFEPU", "CFA4", "FX1", "EX1", "BF-WS", "CF-N", and "VX-1" series manufactured by Japan Polymer Industries Co., Ltd., the "Pyrofil Chopped Fiber" series manufactured by Mitsubishi Chemical Corporation, and the "Tenax-J" series (HT C702, IM C702, etc.) and the "Tenax-A" series (IM P303, HT P722, etc.) manufactured by Teijin Limited.

[0066] When the resin composition of the present invention contains reinforcing fibers, the content thereof in the resin composition is preferably 0.05 to 70 mass%, more preferably 1 to 50 mass%, and even more preferably 3 to 35 mass%, from the viewpoint of improving the mechanical strength and achieving both a low dielectric constant and a low dielectric loss tangent.

[0067] <Additives> The resin composition of the present invention may contain additives such as fillers other than the reinforcing fibers, delustering agents, nucleating agents, plasticizers, antistatic agents, coloring inhibitors, antigelling agents, flame retardants, colorants, sliding property improvers, antioxidants, ultraviolet absorbers, conductive agents, and resin modifiers, as needed. The content of the additives is not particularly limited, but from the viewpoint of exhibiting the effects of the additives while maintaining the physical properties derived from the liquid crystal polymer (A) and the polyimide resin (B), the content of the additives in the resin composition is usually 50% by mass or less, preferably 0.0001 to 30% by mass, more preferably 0.0001 to 15% by mass, and even more preferably 0.001 to 10% by mass.

[0068] The resin composition of the present invention may take any form, but is preferably in the form of pellets. Since the liquid crystal polymer (A) and the polyimide resin (B) have thermoplastic properties, for example, the liquid crystal polymer (A), the polyimide resin (B), and various optional components as needed can be melt-kneaded in an extruder to extrude strands, and the strands can be cut to pelletize. Furthermore, the obtained pellets can be introduced into various molding machines and thermoformed by the method described below, whereby molded articles having desired shapes can be easily produced.

[0069] <Thermal properties> In the resin composition of the present invention, by containing the liquid crystal polymer (A) and the polyimide resin (B), even if the resin composition contains the liquid crystal polymer (A), it is possible to obtain a resin composition that has appropriate elasticity when melted at high temperatures (200°C or higher) and is easy to handle. From the viewpoint of obtaining the above-mentioned effects, the crystallization temperature Tc of the resin composition of the present invention is preferably 270° C. or higher, more preferably 273° C. or higher. There is no upper limit to Tc, but from the viewpoint of moldability, it is usually 290° C. or lower, preferably 285° C. or lower. The crystallization temperature Tc of the resin composition can be measured by a differential scanning calorimeter, where the resin composition is melted and then cooled at a temperature drop rate of 20°C / min, and the peak-top temperature of the exothermic crystallization peak is measured as the crystallization temperature Tc. Specifically, the crystallization temperature Tc can be measured by the method described in the Examples. When two or more peak-top temperatures are detected as the crystallization temperature Tc, it is preferable that the peak-top temperature of the highest peak be in the above range.

[0070] In the resin composition of the present invention, by containing the liquid crystal polymer (A) and the polyimide resin (B), the resin composition can be made to have faster crystallization and higher moldability than when the polyimide resin (B) is used alone. From the viewpoint of obtaining the above-mentioned effects, the difference (Tm-Tc) between the melting point Tm and the crystallization temperature Tc of the resin composition of the present invention is preferably not more than 80° C., more preferably not more than 60° C., even more preferably not more than 55° C., still more preferably not more than 50° C., still more preferably not more than 46° C., and still more preferably not more than 45° C. The lower limit of Tm-Tc is 0° C. or higher, and the smaller the value of Tm-Tc, the faster the crystallization and the higher the moldability of the resin composition. The melting point Tm of the resin composition can be measured in the same manner as for the polyimide resin (B). When two or more peak top temperatures are detected for the melting point Tm and the crystallization temperature Tc, it is preferable that the highest peak top temperature is used for both Tm and Tc, and the difference between them is within the above range.

[0071] <Electrical characteristics> The resin composition of the present invention contains a liquid crystal polymer (A) and a polyimide resin (B), thereby achieving both a low dielectric constant and a low dielectric loss tangent. For example, the resin composition of the present invention can achieve a dielectric constant of 3.0 or less and a dielectric loss tangent of 0.005 or less at a measurement frequency of 10 GHz. The dielectric constant is preferably 2.90 or less, more preferably 2.85 or less, and the dielectric loss tangent is preferably 0.004 or less. The dielectric constant and dielectric loss tangent can be measured specifically by the methods described in the examples.

[0072] [Molded body] The molded article of the present invention contains the resin composition of the present invention. Since the resin composition of the present invention has thermoplasticity, the molded article of the present invention can be easily produced by thermoforming. Thermoforming methods include injection molding, extrusion molding, blow molding, hot press molding, vacuum forming, pressure forming, laser molding, welding, and adhesion, and any molding method that involves a thermal melting step can be used. The molding temperature varies depending on the thermal properties (melting point and glass transition temperature) of the resin composition, but for example, in injection molding, molding is possible at a molding temperature of less than 400°C and a mold temperature of 220°C or less.

[0073] The method for producing the molded article preferably includes a step of thermoforming the resin composition at a temperature of less than 400° C. Specific procedures include, for example, the following method. First, the liquid crystal polymer (A), the polyimide resin (B), and various optional components are added as needed and dry-blended, and then the mixture is introduced into an extruder, melted preferably at less than 400° C., melt-kneaded in the extruder, and extruded to produce pellets. Alternatively, the polyimide resin (B) may be introduced into the extruder, melted preferably at less than 400° C., and the liquid crystal polymer (A) and various optional components are introduced thereinto, melt-kneaded with the polyimide resin (B) in the extruder, and extruded to produce the pellets. After drying the pellets, they are introduced into various molding machines and thermoformed preferably at a temperature of less than 400° C. to produce a molded article having a desired shape.

[0074] The resin composition of the present invention is easy to melt-knead and extrude, and can achieve both a low dielectric constant and a low dielectric loss tangent. The resin composition and molded articles containing the same can be extrusion-molded, and are expected to be used in applications requiring a low dielectric constant and a low dielectric loss tangent. For example, the resin composition can be used in applications such as fifth-generation mobile communication system (5G) related components, other electrical and electronic components, and insulating films. In addition to the above, examples of applications of the resin composition of the present invention include resin multilayer substrates, circuit boards, flexible printed circuits (FPCs), rigid-flex boards, copper-clad laminates (CCLs), two-layer CCLs, printed wiring boards, multilayer films, capacitor films, converters, power semiconductors, meshes for screen printing, millimeter-wave radar, LEDs, high-frequency connectors, antenna members, etc. Examples of applications of resin compositions containing reinforcing fibers include drones, robot arms, wind power generation blades, radomes, etc. [Example]

[0075] The present invention will now be described in more detail with reference to examples, but the present invention is not limited thereto. Various measurements and evaluations in the production examples and examples were carried out as follows.

[0076] <Infrared spectroscopy (IR measurement)> IR measurements of polyimide resins were carried out using a JEOL "JIR-WINSPEC50."

[0077] <Logarithmic viscosity μ> The polyimide resin was dried at 190 to 200°C for 2 hours, and then 0.100 g of the polyimide resin was dissolved in 20 mL of concentrated sulfuric acid (96%, manufactured by Kanto Chemical Co., Inc.) to prepare a polyimide resin solution for measurement. Measurement was carried out at 30°C using a Cannon-Fenske viscometer. Logarithmic viscosity μ was calculated using the following formula. μ=ln(ts / t0) / C t0: Time when concentrated sulfuric acid flows ts: Flow time of polyimide resin solution C: 0.5 g / dL

[0078] <Melting point, glass transition temperature, crystallization temperature, heat of crystallization> The melting point Tm, glass transition temperature Tg, crystallization temperature Tc, and crystallization heat value ΔHm of the polyimide resin, liquid crystal polymer, and resin composition were measured using a differential scanning calorimeter (DSC-6220 manufactured by SII NanoTechnology Inc.). The sample was subjected to the following thermal history in a nitrogen atmosphere: first heating (heating rate: 10°C / min), then cooling (cooling rate: 20°C / min), then second heating (heating rate: 10°C / min). The heating temperature was from room temperature to 400°C. The melting point Tm was determined by reading the peak top value of the endothermic peak observed during the second heating. The glass transition temperature Tg was determined by reading the value observed during the second heating. The crystallization temperature Tc was determined by reading the peak top value of the exothermic peak observed during cooling. The crystallization heat value ΔHm (mJ / mg) was calculated from the area of ​​the exothermic peak observed during cooling.

[0079] <Crystallization half time> The half-crystallization time of the polyimide resin was measured using a differential scanning calorimeter (DSC-6220, manufactured by SII NanoTechnology Inc.). The polyimide resin was held at 420°C for 10 minutes in a nitrogen atmosphere until it was completely melted, and then rapidly cooled at a rate of 70°C / min. The time required from the appearance of the observed crystallization peak until it reached its peak top was calculated. In Table 1, half-crystallization times of 20 seconds or less are indicated as "<20."

[0080] <Weight average molecular weight> The weight average molecular weight (Mw) of the polyimide resin was measured using a gel permeation chromatography (GPC) measuring device "Shodex GPC-101" manufactured by Showa Denko K.K. under the following conditions. Column: Shodex HFIP-806M Mobile phase solvent: HFIP containing 2 mM sodium trifluoroacetate Column temperature: 40℃ Mobile phase flow rate: 1.0mL / min Sample concentration: approximately 0.1% by mass Detector: IR detector Injection amount: 100μm Calibration curve: Standard PMMA

[0081] <Extrudability of Resin Composition> In the production of each resin composition, the torque, resin temperature, and resin pressure when extruding a strand from the extruder were confirmed. The resin temperature was the temperature at the outlet of the extruder.

[0082] <Flexural strength and flexural modulus> Using the resin compositions produced in each example, molded articles of 80 mm x 10 mm x 4 mm thick, as specified in ISO 316, were prepared by the method described below and used for measurements. A bending test was carried out in accordance with ISO 178 using a Bendograph (manufactured by Toyo Seiki Seisakusho Co., Ltd.) at a temperature of 23°C and a test speed of 2 mm / min, to measure the bending strength and bending modulus.

[0083] <Tensile strength and tensile modulus> Using the resin compositions produced in each example, 1A type test pieces defined in JIS K7161-2:2014 were prepared by the method described below and used for measurements. Using a tensile testing machine (Strograph VG-1E manufactured by Toyo Seiki Co., Ltd.), tensile tests were performed in accordance with JIS K7161-1:2014 and K7161-2:2014 at a temperature of 23°C, a grip distance of 50 mm, and a test speed of 5 mm / min to measure tensile strength and tensile modulus.

[0084] <Heat distortion temperature (HDT)> Using the resin composition produced in each example, a molded body of 80 mm x 10 mm x 4 mm thick was produced by the method described below and used for measurement. The measurement was performed in flatwise in accordance with JIS K7191-1,2:2015. Specifically, the heat distortion temperature was measured using the HDT testing device "Auto-HDT3D-2" (manufactured by Toyo Seiki Seisakusho Co., Ltd.) under the conditions of a support distance of 64 mm, a load of 1.80 MPa, and a heating rate of 120°C / hour.

[0085] <Dielectric constant and dielectric loss tangent> The resin compositions prepared in each example were injection molded to produce molded bodies according to the method described below. These were then machined to obtain test pieces measuring 1.5 mm x 80 mm x 1.5 mm thick. The test pieces were dried in a desiccator and immediately used for measurements. The dielectric constant and dielectric loss tangent were measured in accordance with IEC 62810 using a PNA-L Network Analyzer N5230A manufactured by Agilent Technologies Inc. and a CP531 cavity resonator manufactured by Kanto Electronics Application Development Co., Ltd., using the cavity resonator perturbation method at a temperature of 23°C, humidity of 50%, and a measurement frequency of 10 GHz. The measured values ​​were averaged for duplicate measurements.

[0086] <Water absorption rate> The resin compositions produced in Example 4 and Reference Example 2 were injection molded by the method described below to produce molded articles, which were then cut to obtain test pieces measuring 30 mm x 20 mm x 4 mm thick (approximately 3 g). The test pieces were dried at 50°C for 24 hours and then used to measure water absorption. The water absorption (%) of the test pieces was measured after immersion in water at 23°C for 24 hours in accordance with JIS K7209:2000. The measured value was the average of n = 3.

[0087] <Coefficient of linear thermal expansion (CTE)> The resin compositions produced in Example 4 and Reference Example 2 were injection molded by the method described below to produce molded articles, which were then cut to a size of 5 mm x 4 mm, length 10 mm, and cross-sectional area 20 mm. 2 A test piece was obtained. At this time, the molded body was cut so that the MD of the test piece was the length direction. Using the test piece, TMA measurement was performed using a thermomechanical analyzer "TMA / SS6100" (manufactured by Hitachi High-Tech Science Corporation) in a nitrogen atmosphere with a flow rate of 150 mL / min, under compression mode, a load of 49 mN, and a heating rate of 5°C / min, in the range of 23 to 300°C. The measurement results in the range of 23 to 150°C were analyzed in accordance with JIS K7197:2012 (compression mode), and the CTE in the MD direction of the molded body was determined.

[0088] Production Example 1 (Production of Polyimide Resin 1) A 2L separable flask equipped with a Dean-Stark apparatus, a Liebig condenser, a thermocouple, and a four-paddle impeller was charged with 500g of 2-(2-methoxyethoxy)ethanol (Nippon Nyukazai Co., Ltd.) and 218.12g (1.00mol) of pyromellitic dianhydride (Mitsubishi Gas Chemical Co., Ltd.). After nitrogen flow, the mixture was stirred at 150 rpm to form a uniform suspension. A 500mL beaker was used to prepare a mixed diamine solution by dissolving 49.79g (0.35mol) of 1,3-bis(aminomethyl)cyclohexane (Mitsubishi Gas Chemical Co., Ltd., cis / trans ratio = 7 / 3) and 93.77g (0.65mol) of 1,8-octamethylenediamine (Kanto Chemical Co., Ltd.) in 250g of 2-(2-methoxyethoxy)ethanol. The mixed diamine solution was gradually added using a plunger pump. Although the dropwise addition generated heat, the internal temperature was adjusted to remain within the range of 40 to 80°C. During the dropwise addition of the mixed diamine solution, a nitrogen flow was maintained throughout, and the stirring impeller rotation speed was set to 250 rpm. After the dropwise addition was completed, 130 g of 2-(2-methoxyethoxy)ethanol and 1.284 g (0.010 mol) of n-octylamine (Kanto Chemical Co., Inc.), an end-capping agent, were added and further stirred. At this stage, a pale yellow polyamic acid solution was obtained. Next, the stirring speed was increased to 200 rpm, and the polyamic acid solution in the 2-L separable flask was heated to 190°C. During the temperature increase, precipitation of polyimide resin powder and dehydration associated with imidization were observed between 120 and 140°C. After maintaining the temperature at 190°C for 30 minutes, the solution was allowed to cool to room temperature and then filtered. The obtained polyimide resin powder was washed with 300 g of 2-(2-methoxyethoxy)ethanol and 300 g of methanol, filtered, and then dried in a dryer at 180° C. for 10 hours to obtain 317 g of polyimide resin 1 powder. The obtained polyimide resin 1 powder was melt-kneaded and extruded using a Labo Plastomill (manufactured by Toyo Seiki Seisakusho Co., Ltd.) at a barrel temperature of 350°C and a screw rotation speed of 70 rpm. The strand extruded from the extruder was air-cooled and then pelletized using a pelletizer (Hoshi Plastics Co., Ltd., "Fan Cutter FC-Mini-4 / N"). The obtained pellets were dried at 150°C for 12 hours and then used to produce a molded product. The IR spectrum of polyimide resin 1 was measured, and ν(C=O) 1768, 1697 (cm -1 The characteristic absorption of the imide ring was observed. The inherent viscosity was 1.30 dL / g, Tm was 323°C, Tg was 184°C, Tc was 266°C, the exotherm of crystallization was 21.0 mJ / mg, the half-crystallization time was less than 20 seconds, and Mw was 55,000.

[0089] The composition and evaluation results of the polyimide resin in Production Example 1 are shown in Table 1. The mole percentages of the tetracarboxylic acid component and diamine component in Table 1 are values ​​calculated from the amounts of each component charged when producing the polyimide resin.

[0090] [Table 1]

[0091] The abbreviations in the table are as follows: PMDA; Pyromellitic dianhydride 1,3-BAC; 1,3-bis(aminomethyl)cyclohexane OMDA; 1,8-octamethylenediamine

[0092] Examples 1 to 4 (Preparation and Evaluation of Resin Compositions and Molded Articles) Pellets of liquid crystal polymer 1 containing a repeating structural unit represented by formula (IV) ("UENO LCP A8100" manufactured by Ueno Pharmaceutical Co., Ltd., containing structural units derived from 6-hydroxy-2-naphthoic acid and p-hydroxybenzoic acid, melting point 220°C) and pellets of polyimide resin 1 obtained in Production Example 1 were used in the proportions shown in Table 2. Liquid crystal polymer 1 and polyimide resin 1 were introduced into a co-rotating twin-screw kneading extruder ("HK-25D" manufactured by Parker Corporation, screw diameter D = 25 mmΦ, L / D = 41 (L: screw length)) from a hopper on the inlet side of the extruder, and kneaded under conditions of a cylinder setting temperature of 335°C, a feed rate of 6 kg / h, and a screw rotation speed of 150 rpm, and strands were extruded. At this time, the torque, resin temperature, and resin pressure were confirmed. The strand extruded from the extruder was cooled with water, then pelletized using a pelletizer (Hoshi Plastics Co., Ltd., "Fan Cutter FC-Mini-4 / N") and used for injection molding. Using an injection molding machine (FANUC Corporation's "ROBOSHOT α-S30iA"), injection molding was carried out under conditions of a cylinder setting temperature of 370°C, a mold temperature of 200°C, and an injection speed of 80 mm / s, to produce molded bodies of the specified shape to be used for various evaluations. The obtained molded body was subjected to various evaluations using the methods described above. The results are shown in Tables 2 and 3.

[0093] Reference example 1 In Examples 1 to 4, molded articles were produced in the same manner as in Examples 1 to 4, except that only Liquid Crystal Polymer 1 was used and injection molding was performed under the conditions shown in Table 2 without pelletization, and various evaluations were performed. The results are shown in Tables 2 and 3.

[0094] Reference example 2 In Examples 1 to 4, molded bodies were produced in the same manner as in Examples 1 to 4, except that only pellets of polyimide resin 1 were used, and the water absorption and CTE measurements were carried out. The melting point, glass transition temperature, crystallization temperature, and crystallization heat value of polyimide resin 1 were measured by the same methods as above, and the results are also shown in Table 3.

[0095] [Table 2]

[0096] [Table 3]

[0097] As shown in Table 2, the resin compositions and molded articles of Examples 1 to 4 can achieve both a low dielectric constant of 3.0 or less and a low dielectric loss tangent of 0.005 or less. It is also clear that the higher the proportion of liquid crystal polymer 1, the lower the torque, resin temperature, and resin pressure during strand extrusion, resulting in better extrudability. Furthermore, as shown in Table 3, the resin compositions of Examples 1 to 4 have higher crystallization temperatures Tc than the liquid crystal polymer 1 alone (Reference Example 1) and the polyimide resin 1 alone (Reference Example 2), which means that the elasticity at high temperature melting is not reduced too much and the handling properties are excellent. Furthermore, the resin compositions of Examples 1 to 4 have smaller Tm-Tc values ​​than Reference Example 2, which suggests that the crystallization is faster and the moldability is improved. Comparison between Example 4 and Reference Example 2 reveals that the molded article made from the resin composition of the present invention has low water absorption, a small CTE value, and excellent dimensional stability when heated.

[0098] Examples 5 to 10 (Preparation and Evaluation of Carbon Fiber Reinforced Resin Compositions and Molded Articles) Pellets of the liquid crystal polymer 1 (UENO LCP A8100 manufactured by Ueno Pharmaceutical Co., Ltd.), pellets or powder of the polyimide resin 1 obtained in Production Example 1 (pellets were used in Examples 5 and 6, and powder in Examples 7 to 10), talc (Nippon Talc Co., Ltd.'s Nano Ace D-800, average particle size (D50): 0.8 μm) as an inorganic filler, and carbon fiber (Tenax-J IM C702 manufactured by Teijin Limited, average fiber length: 6 mm, amount of sizing agent: 1.8%) were used in the proportions shown in Table 3. Liquid crystal polymer 1, polyimide resin 1, and talc were introduced into the extruder from the inlet hopper of a co-rotating twin-screw kneading extruder ("HK-25D" manufactured by Parker Corporation, screw diameter D = 25 mmΦ, L / D = 41 (L: screw length)), and carbon fiber was side-fed. The mixture was kneaded under the conditions of a cylinder temperature setting of 350°C, a feed rate of 6 kg / h, and a screw rotation speed of 150 rpm, and a strand was extruded. During this process, the torque, resin temperature, and resin pressure were confirmed. The strand extruded from the extruder was cooled with water, then pelletized using a pelletizer (Hoshi Plastics Co., Ltd., "Fan Cutter FC-Mini-4 / N") and used for injection molding. Using an injection molding machine (FANUC Corporation's "ROBOSHOT α-S30iA"), injection molding was carried out under conditions of a cylinder temperature setting of 370°C, a mold temperature of 200°C, and an injection speed of 30 mm / s to produce molded bodies of the specified shape to be used for various evaluations. The obtained molded body was subjected to various evaluations using the methods described above. The results are shown in Table 4.

[0099] [Table 4]

[0100] Comparison of Table 2 and Table 4 reveals that the flexural strength, flexural modulus, and HDT of the resin composition of the present invention can be improved by reinforcing it with carbon fibers.

[0101] Examples 11 to 16 (Preparation and Evaluation of Glass Fiber Reinforced Resin Compositions and Molded Articles) Pellets of glass fiber reinforced liquid crystal polymer ("UENO LCP 6030G-NCSL" manufactured by Ueno Pharmaceutical Co., Ltd., melting point 320°C) containing 70% by mass of liquid crystal polymer 2 having a repeating structural unit represented by formula (IV) and 30% by mass of glass fiber, and pellets of polyimide resin 1 obtained in Production Example 1 were used in the proportions shown in Table 5. Glass fiber reinforced liquid crystal polymer and polyimide resin 1 were introduced into the extruder from the inlet hopper of a co-rotating twin-screw kneading extruder ("HK-25D" manufactured by Parker Corporation, screw diameter D = 25 mmΦ, L / D = 41 (L: screw length)), and kneaded under conditions of a cylinder setting temperature of 335°C, a feed rate of 6 kg / h, and a screw rotation speed of 150 rpm, and strands were extruded. At this time, the torque, resin temperature, and resin pressure were confirmed. The strand extruded from the extruder was cooled with water, then pelletized using a pelletizer (Hoshi Plastics Co., Ltd., "Fan Cutter FC-Mini-4 / N") and used for injection molding. Using an injection molding machine (FANUC Corporation's "ROBOSHOT α-S30iA"), injection molding was carried out under conditions of a cylinder temperature setting of 370°C, a mold temperature of 200°C, and an injection speed of 30 mm / s to produce molded bodies of the specified shape to be used for various evaluations. The obtained molded body was subjected to various evaluations using the methods described above. The results are shown in Table 5.

[0102] Reference example 3 In Examples 11 to 16, molded articles were produced in the same manner as in Examples 11 to 16, except that only glass fiber reinforced liquid crystal polymer was used and injection molding was performed without pelletization, and various evaluations were performed. The results are shown in Table 5.

[0103] [Table 5]

[0104] As shown in Table 5, even when the resin composition of the present invention contains glass fibers, it is possible to achieve both a low dielectric constant and a low dielectric loss tangent. [Industrial Applicability]

[0105] The resin composition of the present invention contains a liquid crystal polymer, yet has excellent handleability when molten, is easy to melt-knead, and is extrudable, and can achieve both a low dielectric constant and a low dielectric loss tangent. The resin composition and molded articles containing the same can be extrusion-molded, and are expected to be used in applications requiring a low dielectric constant and a low dielectric loss tangent. For example, the resin composition can be used in components related to fifth-generation mobile communication systems (5G) and sixth-generation mobile communication systems (6G), as well as other electrical and electronic components, insulating films, and the like.

Claims

1. A resin composition comprising: a liquid crystal polymer (A) containing at least one repeating structural unit selected from the group consisting of repeating structural units represented by the following formulas (I) to (IV); and a polyimide resin (B) containing a repeating structural unit represented by the following formula (1) and a repeating structural unit represented by the following formula (2), wherein the content of the repeating structural unit of the formula (1) relative to the total of the repeating structural unit of the formula (1) and the repeating structural unit of the formula (2) is 20 to 70 mol %, the polyimide resin (B) is a crystalline thermoplastic resin, a mass ratio [(A) / (B)] of the liquid crystal polymer (A) to the polyimide resin (B) is in the range of 0.1 / 99.9 to 70 / 30; the total content of the liquid crystal polymer (A) and the polyimide resin (B) in the resin composition is 70% by mass or more; A resin composition having a relative dielectric constant of 2.76 or more and 3.51 or less and a dielectric loss tangent of 0.0027 or more and 0.005 or less at a measurement frequency of 10 GHz. 【Chemistry 1】 (a, b, and c represent the average number of repeating structural units.) 【Chemistry 2】 (R １ is a divalent group having 6 to 22 carbon atoms and containing at least one alicyclic hydrocarbon structure. ２ is a divalent chain aliphatic group having 5 to 16 carbon atoms. １ and X ２ are each independently a tetravalent group containing at least one aromatic ring and having 6 to 22 carbon atoms.

2. The resin composition according to claim 1, wherein the mass ratio [(A) / (B)] of the liquid crystal polymer (A) to the polyimide resin (B) is in the range of 0.1 / 99.9 to 50 / 50.

3. The resin composition according to claim 1 or 2, wherein the liquid crystal polymer (A) has a melting point of 180°C or higher and 350°C or lower.

4. In the polyimide resin (B), the content ratio of the repeating structural unit of the formula (1) to the total of the repeating structural unit of the formula (1) and the repeating structural unit of the formula (2) is 20 mol% or more and less than 40 mol%. The resin composition according to any one of claims 1 to 3.

5. The resin composition according to any one of claims 1 to 4, further comprising reinforcing fibers.

6. The resin composition according to any one of claims 1 to 5, having a relative dielectric constant of 3.0 or less at a measurement frequency of 10 GHz.

7. A molded article comprising the resin composition according to any one of claims 1 to 6.

Images