JP2021161286A - Low dielectric resin composition, molding, film, and flexible printed wiring board - Google Patents

Abstract

To provide a low dielectric resin composition which has good melt processibility and is excellent in low dielectric characteristics in a high frequency band, a molding and a film composed of the low dielectric resin composition, and a flexible printed wiring board including the film composed of the low dielectric resin composition.SOLUTION: A low dielectric resin composition contains a liquid crystal polymer (A) and graft modified polyolefin (B) having a polar group, and is formed with such a sea island structure in which an island phase, which is a non-continuous region, is dispersed in a sea phase, which is a continuous region. The sea phase in the sea island structure is formed from any one of the liquid crystal polymer (A) and the graft modified polyolefin (B) having the polar group, and a size of the island phase is 20 μm or less.SELECTED DRAWING: Figure 1

Description

The present invention relates to a flexible printed wiring board including a low-dielectric resin composition, a molded product and a film made of the low-dielectric resin composition, and a film made of the low-dielectric resin composition.

In recent years, communication devices such as smartphones and electronic devices such as next-generation televisions have been required to transmit and receive large amounts of data at high speed. Along with this, the frequency of electric signals is increasing. Specifically, in the field of wireless communication, the introduction of the 5th generation mobile communication system (5G) is expected around 2020. When introducing the 5th generation mobile communication system, the use of a high frequency band of 10 GHz or more is being considered.

However, as the frequency of the signal used increases, the quality of the output signal, which can lead to misrecognition of information, deteriorates, that is, the transmission loss increases. This transmission loss consists of a conductor loss caused by a conductor and a dielectric loss caused by an insulating resin constituting an electric / electronic component such as a substrate in an electronic device or a communication device. The conductor loss is 0 at the frequency used. Since the fifth power and the dielectric loss are proportional to the first power of the frequency, the influence of this dielectric loss becomes very large in the high frequency band, particularly in the GHz band.

Therefore, in order to reduce the transmission loss, a low-dielectric material having a low relative permittivity and a dielectric loss tangent, which are factors related to the dielectric loss, is required. Under these circumstances, the use of, for example, a liquid crystal polymer has been studied as a low-dielectric material used in a high frequency band.

However, even for low-dielectric resins such as liquid crystal polymers, further low-dielectric properties are required in order to further reduce transmission loss. The liquid crystal polymer also has a problem that it is difficult to melt process due to its anisotropy. For example, when a liquid crystal polymer is formed into a film by an extrusion method, which is a typical film manufacturing method, the molten liquid crystal polymer discharged from a die immediately drips due to a decrease in melt viscosity due to a shearing force in the discharge direction. It is difficult to pick up the film. Even if the film could be picked up, the resulting film would be very liable to tear due to the orientation of the liquid crystal polymer in the film. Further, there is a problem that a resin lump is likely to be generated in the lip portion of the T-die during extrusion molding. Further, the anisotropy of the liquid crystal polymer may make it difficult to produce pellets by cutting the strands. Specifically, for example, there is a problem that the strand cannot be cut, or even if the strand can be cut, a clean cut surface cannot be formed and whiskers are likely to occur on the pellet. The non-uniform shape of the pellets and the whiskers on the pellets contribute to the instability of weighing the liquid crystal polymer during the molding process of the liquid crystal polymer.

Under these circumstances, a composition in which a polyolefin resin is blended with a liquid crystal polymer to improve molding processability and anisotropy has been studied. For example, Patent Document 1 discloses a liquid crystal polyester resin composition film containing a liquid crystal polyester having a specific melt viscosity and a thermoplastic resin. Patent Document 1 describes a copolymer of ethylene and glycidyl methacrylate as an example of the thermoplastic resin. In the technique described in Patent Document 1, a resin having a specific melt viscosity is used as each resin component, and a thermoplastic resin whose flow start temperature is not lower than the same temperature of the liquid crystal polyester by 10 ° C. or more is used. As a result, the obtained liquid crystal polyester resin composition is excellent in gas barrier property and film moldability. Patent Document 2 discloses a polyester resin composition having flexibility and impact resistance, which contains a liquid crystal resin, an olefin resin and a non-liquid crystal polyester resin. In the polyester resin composition, the non-liquid crystal polyester resin forms a continuous phase, and the olefin resin is dispersed in the continuous phase (sea phase) as an island phase.

Japanese Unexamined Patent Publication No. 9-012744 Japanese Unexamined Patent Publication No. 2005-0230994

However, the above-mentioned blend of polyolefin resins is not always effective in improving the film formability of the liquid crystal polymer and imparting even better low dielectric properties. As shown in Examples and Comparative Examples described later, for example, when a copolymer of ethylene and glycidyl methacrylate is blended with a liquid crystal polymer as described in Patent Document 1, the obtained liquid crystal polymer composition has a large dielectric loss tangent. May become. Patent Document 2 describes grafts as well as copolymerization as a method for introducing a functional group into polyolefin. However, in the resin composition disclosed in Patent Document 2, the non-liquid polyester resin is a continuous phase (sea phase). Therefore, the resin composition disclosed in Patent Document 2 cannot be expected to have the heat resistance of the liquid crystal polymer and the low dielectric property of the polyolefin resin. In the first place, these inventions aim at improving the moldability, impact resistance, gas barrier property, etc. of the resin composition. Therefore, the above-mentioned Patent Documents 1 and 2 do not mention any dielectric properties.

The present invention has been made in view of the above problems, and is formed by using a low-dielectric resin composition having good melt processability and excellent low-dielectric properties in a high-frequency band, and the low-dielectric resin composition. An object of the present invention is to provide a molded product and a film, and a flexible printed wiring board containing the film.

As a result of diligent studies to solve the above problems, the present inventor blends a graft-modified polyolefin (B) having a polar group with a liquid crystal polymer and forms a specific sea-island structure to heat the liquid crystal polymer. The present invention has been completed by finding that a resin composition having excellent melt processability, particularly film formability, and low dielectric properties can be obtained without impairing the above.

That is, the present invention provides the following (1) to (12).
(1) A sea-island structure containing the liquid crystal polymer (A) and the graft-modified polyolefin (B) having a polar group, in which the discontinuous island phase is dispersed in the continuous sea phase is formed. A low-dielectric resin composition
A low-dielectric resin composition in which the sea phase in the sea-island structure is formed of either a liquid crystal polymer (A) or a graft-modified polyolefin (B) having a polar group, and the size of the island phase is 20 μm or less.
(2) The relative permittivity at a frequency of 10 GHz is lower than the relative permittivity of the liquid crystal polymer (A) at a frequency of 10 GHz, and the dielectric loss tangent at a frequency of 10 GHz is higher than the dielectric loss tangent of the graft-modified polyolefin (B) at a frequency of 10 GHz. The low dielectric resin composition according to (1), which has a low value.
(3) The low-dielectric resin composition according to (1) or (2), wherein the relative permittivity at a frequency of 10 GHz is 2.80 or less.
(4) The low dielectric resin composition according to any one of (1) to (3), wherein the dielectric loss tangent at a frequency of 10 GHz is 0.0025 or less.
(5) The low-dielectric resin composition according to any one of (1) to (4), which further contains an olefin elastomer (C).
(6) The low-dielectric resin composition according to any one of (1) to (5), wherein the polar group is an epoxy group.
(7) The low-dielectric resin device according to any one of (1) to (6), wherein the graft-modified polyolefin (B) is a polyolefin graft-modified with glycidyl (meth) acrylate and styrene.
(8) The method for producing a low-dielectric resin composition according to any one of (1) to (7), which comprises a step of melt-kneading the liquid crystal polymer (A) and the graft-modified polyolefin (B) having a polar group. ..
(9) A molded product formed by using the low-dielectric resin composition according to any one of (1) to (7).
(10) A film formed by using the low-dielectric resin composition according to any one of (1) to (7).
(11) A flexible printed wiring board containing the film according to (10).

According to the present invention, a low-dielectric resin composition having good melt processability, particularly film formability, and excellent low-dielectric properties in a high-frequency band, a molded product and a film made of the low-dielectric resin composition, and the like. A flexible printed wiring board including a film made of a low-dielectric resin composition can be provided.

It is a scanning electron micrograph (magnification 1000 times) of the cross section of the sample which is the thermoplastic resin composition which concerns on this invention, and the liquid crystal polymer (A) forms an island phase. It is a scanning electron micrograph (magnification 1000 times) of the cross section of the sample which is the thermoplastic resin composition which concerns on this invention, and the liquid crystal polymer (A) forms a sea phase. A scanning type of a cross section of a sample of a thermoplastic resin composition containing a liquid crystal polymer (A) and a graft-modified polyolefin (B), in which a co-continuous structure is formed and an island phase is formed in a part of a continuous region. It is an electron micrograph (magnification 1000 times).

≪Low dielectric resin composition≫
The low-dielectric resin composition is a resin composition containing a liquid crystal polymer (A) and a graft-modified polyolefin (B) having a polar group. Hereinafter, the graft-modified polyolefin (B) having a polar group is also simply referred to as “graft-modified polyolefin (B)”. In the above low-dielectric resin composition, a sea-island structure in which discontinuous island phases are dispersed in a continuous sea phase is formed. Further, the sea phase in the sea-island structure is formed by either the liquid crystal polymer (A) or the graft-modified polyolefin (B), and the size of the island phase is 20 μm or less.

The relative permittivity of the low-dielectric resin composition at 10 GHz is preferably a value lower than the relative permittivity of the liquid crystal polymer (A) at a frequency of 10 GHz. Further, the dielectric loss tangent of the low dielectric resin composition at 10 GHz is preferably equal to or less than the value of the dielectric loss tangent of the graft-modified polyolefin (B) at a frequency of 10 GHz.

The relative permittivity of the low-dielectric resin composition at a frequency of 10 GHz is preferably 2.80 or less. The dielectric loss tangent of the low dielectric resin composition at 10 GHz is preferably 0.0025 or less.

The above-mentioned low-dielectric resin composition is suitably used in applications such as electric and electronic parts, information communication devices, and parts of the information communication device used in a high frequency band by taking advantage of the low dielectric property.

The resin composition containing the liquid crystal polymer and the graft-modified polyolefin has various phases depending on various conditions such as the mixing ratio of the two, the melting point, the difference between the melting points of the two, the temperature at the time of mixing, and the modification rate of the graft-modified polyolefin. A state (phase structure) can be formed. In the above low-dielectric resin composition, a sea-island structure in which discontinuous island phases are dispersed in a continuous sea phase is formed, and the sea phase in the sea-island structure contains a liquid crystal polymer (A) and a polar group. It is formed of only one of the graft-modified polyolefins (B) having, and a co-continuous structure is not formed. Moreover, the size of the island phase is 20 μm or less.
In such a phase state, the anisotropy derived from the properties of the liquid crystal polymer (A) is alleviated, and the melt processability of the low-dielectric resin composition is good. The term "melt processability" as used herein means that it is easy or possible to melt and process a polymer using conventional processing equipment such as an extruder and an injection molding machine.

Regarding the sea-island structure in the low-dielectric resin composition, either the liquid crystal polymer (A) or the graft-modified polyolefin (B) may be a component constituting the sea phase (continuous region).
Since the liquid crystal polymer (A) forms a sea phase, it is easy to exhibit excellent heat resistance derived from the liquid crystal polymer (A) as well as excellent melt processability. Since the graft-modified polyolefin (B) forms a sea phase, it tends to exhibit low dielectric properties as well as excellent melt processability.

In addition, "the size of the island phase is 20 μm or less" means that the size of the island phase of 90% or more, usually 95% or more, typically 99% or more of the entire island phase which is a discontinuous region is 20 μm or less. Show that. Here, the "size" generally refers to the diameter of the phase, but when the shape of the island phase is significantly different from the circular shape, the major axis (the length of the long side of the circumscribed rectangle) is defined as the "size".
As a method for confirming the size of the island phase of the present invention, it can be confirmed by any method. For example, as in the examples described later, a film formed by using a low dielectric resin composition is heated. Examples thereof include a method of embedding with a curable resin, polishing a cross section in the thickness direction with an ion beam to obtain a cross section of the film, and observing the cross section of the film with a scanning electron microscope.
The size of these island phases usually reflects the compatibility between the blended resins, and in general, the higher the compatibility, the smaller the size of the island phases tends to be. The island phase size of the low-dielectric resin composition is preferably 15 μm or less, particularly preferably 10 μm or less, and more preferably 5 μm or less.

The low-dielectric resin composition is produced by mixing the liquid crystal polymer (A) and the graft-modified polyolefin (B).
The method of mixing the liquid crystal polymer (A) and the graft-modified polyolefin (B) is not particularly limited. A preferred mixing method includes a method using a melt-kneading device such as a single-screw extruder or a twin-screw extruder.
The condition for mixing the liquid crystal polymer (A) and the graft-modified polyolefin (B) is that the liquid crystal polymer (A) and the graft-modified polyolefin (B) can be uniformly mixed, and each component contained in the low dielectric resin composition can be mixed. The condition is not particularly limited as long as it does not undergo excessive thermal decomposition or sublimation. When a melt-kneading device is used, for example, the temperature is preferably 5 ° C. or higher and 100 ° C. or lower, more preferably 10 ° C. or higher, higher than the melting point of the liquid crystal polymer (A) and the melting point of the graft-modified polyolefin. Melting and kneading is performed at a temperature as high as 50 ° C. or lower.

The low-dielectric resin composition may contain other resins other than the liquid crystal polymer (A) and the graft-modified polyolefin (B) as long as the object of the present invention is not impaired. The total ratio of the mass of the liquid crystal polymer (A) and the mass of the graft-modified polyolefin (B) to the total mass of the resin component contained in the low dielectric resin composition is typically preferably 80% by mass, 90% by mass. By mass% or more is more preferable, 95% by mass or more is further preferable, and 100% by mass is particularly preferable.

Examples of other resins include ungrafted polyolefins, non-liquid polyesters such as polyethylene terephthalate and polybutylene terephthalate, polyamides, polyesteramides, polyimides, polyamideimides, polycarbonates, polyacetals, polyphenylene sulfides, polyphenylene ethers, polysulfones. , Polyethersulfone, polyetherimide, silicone resin, fluororesin and the like.

An inorganic filler can be added to the low-dielectric resin composition, if necessary. Inorganic fillers include calcium carbonate, talc, clay, silica, magnesium carbonate, barium sulfate, titanium oxide, alumina, montmorillonite, gypsum, glass flakes, glass fibers, milled glass fibers, carbon fibers, alumina fibers, silica alumina fibers, Examples thereof include aluminum borate whisker and potassium titanate fiber. The inorganic filler may be used alone or in combination of two or more.
The amount of these inorganic fillers used is appropriately determined according to the application of the low-dielectric resin composition as long as the low-dielectric properties of the low-dielectric resin composition are not impaired. For example, when a film is formed using a low-dielectric resin composition, the upper limit of the amount of the inorganic filler used is set within a range that does not significantly impair the mechanical strength of the film.

The low dielectric resin composition may further include organic fillers, antioxidants, heat stabilizers, light stabilizers, flame retardants, lubricants, antistatic agents, colorants, rust preventives, cross-linking agents, as required. Various additives such as a foaming agent, a fluorescent agent, a surface smoothing agent, a surface gloss improving agent, and a mold release improving agent can be blended.
These additives may be used alone or in combination of two or more.

Hereinafter, the liquid crystal polymer (A) and the graft-modified polyolefin (B) will be described.

<Liquid crystal polymer>
The liquid crystal polymer is a polymer that exhibits optical anisotropy when melted, and a polymer recognized by those skilled in the art as a thermotropic liquid crystal polymer can be used without particular limitation. The optical anisotropy at the time of melting can be confirmed by a conventional polarization inspection method using an orthogonal polarizer.

The liquid crystal polymer is typically produced by polycondensing a monomer mixture containing an acylated product of a monomer having a phenolic hydroxyl group. The polycondensation is preferably carried out in the presence of a catalyst. Examples of the catalyst include metal compounds such as magnesium acetate, stannous acetate, tetrabutyl titanate, lead acetate, sodium acetate, potassium acetate and antimony trioxide, and nitrogen-containing heterocyclic compounds such as 1-methylimidazole. Be done.
The amount of the catalyst used is, for example, preferably 0.1 part by mass or less with respect to 100 parts by mass of the amount of the monomer mixture (A).

As described above, the monomer mixture is a mixture of monomers containing an acylated product of a monomer having a phenolic hydroxyl group. The monomer mixture may contain a monomer having no phenolic hydroxyl group such as an aromatic dicarboxylic acid typified by terephthalic acid or isophthalic acid.

As a method for preparing the monomer mixture, a method of acylating a monomer mixture containing a monomer having a phenolic hydroxyl group to obtain a monomer mixture containing an acylated product of a monomer having a phenolic hydroxyl group is preferable in terms of cost and production time.

Examples of the constituent units constituting the liquid crystal polymer include aromatic oxycarbonyl units, aromatic dicarbonyl units, aromatic dioxy units, aromatic aminooxy units, aromatic diamino units, aromatic aminocarbonyl units, and aliphatic dioxy units. Can be mentioned.
An amide bond or a thioester bond may be included as a bond other than the liquid crystal polymer and the ester bond.

The aromatic oxycarbonyl unit is a unit derived from an aromatic hydroxycarboxylic acid.
Preferable specific examples of the aromatic hydroxycarboxylic acid include p-hydroxybenzoic acid, m-hydroxybenzoic acid, o-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid, 5-hydroxy-2-naphthoic acid, 3 -Hydroxy-2-naphthoic acid, 4'-hydroxyphenyl-4-benzoic acid, 3'-hydroxyphenyl-4-benzoic acid, 4'-hydroxyphenyl-3-benzoic acid, alkyl, alkoxy or halogen substituents thereof Can be mentioned.
Ester derivatives of aromatic hydroxycarboxylic acids, ester-forming derivatives such as acid halides can also be preferably used in the same manner as aromatic hydroxycarboxylic acids.
Among these aromatic hydroxycarboxylic acids, p-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid are preferable because the mechanical properties and melting point of the obtained liquid crystal polymer can be easily adjusted.

The aromatic dicarbonyl repeating unit is a unit derived from an aromatic dicarboxylic acid.
Preferable specific examples of the aromatic dicarboxylic acid include terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 1,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, and the like. And aromatic dicarboxylic acids such as 4,4'-dicarboxybiphenyl, alkyl, alkoxy or halogen substituents thereof.
Ester derivatives of aromatic dicarboxylic acids, ester-forming derivatives such as acid halides can also be preferably used in the same manner as aromatic dicarboxylic acids.
Among these aromatic dicarboxylic acids, terephthalic acid and 2,6-naphthalenedicarboxylic acid are preferable because the mechanical properties, heat resistance, melting point temperature, and moldability of the obtained liquid crystal polymer can be easily adjusted to appropriate levels.

Aromatic dioxy repeating units are units derived from aromatic diols.
Suitable specific examples of aromatic diols include hydroquinone, resorcinol, 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 1,4-dihydroxynaphthalene, and 4,4'-dihydroxybiphenyl. , 3,3'-Dihydroxybiphenyl, 3,4'-dihydroxybiphenyl, 4,4'-dihydroxybiphenyl ether, alkyl, alkoxy or halogen substituents thereof and the like.
Among these aromatic diols, hydroquinone, resorcin, and 4,4'-dihydroxybiphenyl are preferable from the viewpoint of reactivity at the time of polycondensation, characteristics of the obtained liquid crystal polymer, and the like.

Aromatic aminooxy units are units derived from aromatic hydroxyamines.
Suitable specific examples of aromatic hydroxyamines include p-aminophenol, m-aminophenol, 4-amino-1-naphthol, 5-amino-1-naphthol, 8-amino-2-naphthol, 4-amino-. Aromatic hydroxyamines such as 4'-hydroxybiphenyl, alkyl, alkoxy or halogen substituents thereof and the like can be mentioned.

Aromatic diamino units are units derived from aromatic diamines.
Preferable specific examples of the aromatic diamine include aromatic diamines such as p-phenylenediamine, m-phenylenediamine, 1,5-diaminonaphthalene and 1,8-diaminonaphthalene, and alkyl, alkoxy or halogen substituents thereof. Can be mentioned.

Aromatic aminocarbonyl units are units derived from aromatic aminocarboxylic acids.
Suitable specific examples of aromatic aminocarboxylic acids include aromatic aminocarboxylic acids such as p-aminobenzoic acid, m-aminobenzoic acid, 6-amino-2-naphthoic acid, and alkyl, alkoxy or halogen substituents thereof. Can be mentioned.
Ester derivatives of aromatic aminocarboxylic acids, ester-forming derivatives such as acid halides can also be suitably used as monomers for producing liquid crystal polymers.

Specific examples of the monomer giving an aliphatic dioxy unit include aliphatic diols such as ethylene glycol, 1,4-butanediol, and 1,6-hexanediol, and acylates thereof.
In addition, a polymer containing an aliphatic dioxy unit such as polyethylene terephthalate or polybutylene terephthalate can be used as an aromatic oxycarboxylic acid, an aromatic dicarboxylic acid, an aromatic diol, and an acylated product, an ester derivative, or an acid halogen thereof. A liquid crystal polymer containing an aliphatic dioxy unit can also be obtained by reacting with a compound or the like.

The liquid crystal polymer may contain a thioester bond. Examples of the monomer giving such a bond include mercapto aromatic carboxylic acid, aromatic dithiol, hydroxyaromatic thiol and the like.
The amounts of these monomers used are aromatic oxycarbonyl repeating units, aromatic dicarbonyl repeating units, aromatic dioxy repeating units, aromatic aminooxy repeating units, aromatic diamino repeating units, aromatic aminocarbonyl repeating units, It is preferably 10 mol% or less based on the total amount of the aromatic oxydicarbonyl repeating unit and the monomer giving the aliphatic dioxy repeating unit.

Preferable examples of the liquid crystal polymer include the following 1) to 26) and the like.
1) 4-Hydroxybenzoic acid / 2-hydroxy-6-naphthoic acid copolymer 2) 4-hydroxybenzoic acid / terephthalic acid / 4,4'-dihydroxybiphenyl copolymer 3) 4-hydroxybenzoic acid / terephthalic acid / Isophthalic acid / 4,4'-dihydroxybiphenyl copolymer 4) 4-hydroxybenzoic acid / terephthalic acid / isophthalic acid / 4,4'-dihydroxybiphenyl / hydroquinone copolymer 5) 4-hydroxybenzoic acid / terephthalic acid / Hydroquinone copolymer 6) 4-hydroxybenzoic acid / terephthalic acid / 4,4'-dihydroxybiphenyl / hydroquinone copolymer 7) 2-hydroxy-6-naphthoic acid / terephthalic acid / hydroquinone copolymer 8) 4- Hydroxybenzoic acid / 2-hydroxy-6-naphthic acid / terephthalic acid / 4,4'-dihydroxybiphenyl copolymer 9) 2-hydroxy-6-naphthoic acid / terephthalic acid / 4,4'-dihydroxybiphenyl copolymer 10) 4-Hydroxybenzoic acid / 2-hydroxy-6-naphthoic acid / terephthalic acid / hydroquinone copolymer 11) 4-hydroxybenzoic acid / 2-hydroxy-6-naphthoic acid / terephthalic acid / hydroquinone / 4,4' -Dihydroxybiphenyl copolymer 12) 4-hydroxybenzoic acid / 2,6-naphthalenedicarboxylic acid / 4,4'-dihydroxybiphenyl copolymer 13) 4-hydroxybenzoic acid / terephthalic acid / 2,6-naphthalenedicarboxylic acid / Hydroquinone copolymer 14) 4-hydroxybenzoic acid / 2,6-naphthalenedicarboxylic acid / Hydroquinone copolymer 15) 4-hydroxybenzoic acid / 2-hydroxy-6-naphthoic acid / 2,6-naphthalenedicarboxylic acid / Hydroquinone copolymer 16) 4-hydroxybenzoic acid / terephthalic acid / 2,6-naphthalenedicarboxylic acid / hydroquinone / 4,4'-dihydroxybiphenyl copolymer 17) 4-hydroxybenzoic acid / terephthalic acid / 4-aminophenol Copolymer 18) 2-Hydroxy-6-naphthoic acid / terephthalic acid / 4-aminophenol copolymer 19) 4-hydroxybenzoic acid / 2-hydroxy-6-naphthoic acid / terephthalic acid / 4-aminophenol co-weight Combined 20) 4-hydroxybenzoic acid / terephthalic acid / 4,4'-dihydroxybiphenyl / 4-aminophenol copolymer 21) 4-hydroxybenzoic acid / terephthalic acid / ethylene glycol copolymer 22) 4-hi Droxybenzoic acid / terephthalic acid / 4,4'-dihydroxybiphenyl / ethylene glycol copolymer 23) 4-hydroxybenzoic acid / 2-hydroxy-6-naphthoic acid / terephthalic acid / ethylene glycol copolymer 24) 4-hydroxy Benzoic acid / 2-hydroxy-6-naphthic acid / terephthalic acid / 4,4'-dihydroxybiphenyl / ethylene glycol copolymer 25) 4-hydroxybenzoic acid / terephthalic acid / 2,6-naphthalenedicarboxylic acid / 4,4 '-Dihydroxybiphenyl copolymer 26) 2-Hydroxy-6-naphthoic acid / 2,6-naphthalenedicarboxylic acid / 4,4'-dihydroxybiphenyl / hydroquinone copolymer.
The liquid crystal polymer is more preferably a total aromatic liquid crystal polymer, that is, a polymer containing no aliphatic unit such as ethylenedioxy unit. By using the all-aromatic liquid crystal polymer as a component, the low-dielectric resin composition becomes more excellent in heat resistance.

As described above, it is preferable to acylate a monomer mixture containing a monomer having a phenolic hydroxyl group to obtain a monomer mixture containing an acylated product of a monomer having a phenolic hydroxyl group. Acylation is preferably carried out by reacting a phenolic hydroxyl group with a fatty acid anhydride. As the fatty acid anhydride, for example, acetic anhydride, propionic anhydride and the like can be used. Acetic anhydride is preferably used from the viewpoint of price and handleability.

The amount of the fatty acid anhydride used is preferably 1.0 times or more and 1.15 times or less, and more preferably 1.03 times or more and 1.10 times or less with respect to the amount of phenolic hydroxyl groups.

A monomer mixture containing a monomer having a phenolic hydroxyl group and the above-mentioned fatty acid anhydride are mixed and acylated by heating to obtain a monomer mixture containing an acylated product of a monomer having a phenolic hydroxyl group.

A liquid crystal polymer can be obtained by heating the monomer mixture containing the acylated product of the monomer having a phenolic hydroxyl group obtained as described above and distilling off the fatty acid produced as a by-product by polycondensation.
When a liquid crystal polymer is produced only by melt polycondensation, the temperature of melt polycondensation is preferably 150 ° C. or higher and 400 ° C. or lower, and preferably 250 ° C. or higher and 370 ° C. or lower.
When a liquid crystal polymer is produced in two steps of melt polycondensation and solid phase polymerization described later, the temperature of melt polycondensation is preferably 120 ° C. or higher and 350 ° C. or lower, and preferably 200 ° C. or higher and 300 ° C. or lower. The time of the polycondensation reaction is not particularly limited as long as a liquid crystal polymer having a desired melting point or a desired molecular weight can be obtained. For example, the reaction time of polycondensation is preferably 30 minutes or more and 5 hours or less.
If necessary, the liquid crystal polymer produced by the above method may be subjected to polycondensation by heating in a solidified state (solid phase) in order to further increase the molecular weight.

The liquid crystal polymer (A) is obtained by the above method. The melting point of the liquid crystal polymer (A) is not particularly limited as long as it does not impair the object of the present invention. The melting point of the liquid crystal polymer (A) is preferably 250 ° C. or higher, more preferably 280 ° C. or higher. On the other hand, the melting point of the liquid crystal polymer (A) is preferably 400 ° C. or lower, preferably 350 ° C. or lower, from the viewpoint of processability and the suppression of decomposition of the graft-modified polyolefin (B) during the production of the low-dielectric resin composition. More preferred.
The melting point of the liquid crystal polymer (A) is, for example, the temperature obtained from the crystal melting peak measured at a heating rate of 20 ° C./min by a differential scanning calorimetry (hereinafter abbreviated as DSC). .. More specifically, after observing the heat absorption peak temperature (Tm1) observed when the liquid crystal polymer sample is measured at a temperature rising condition of 20 ° C./min from room temperature, the temperature is 20 ° C. or higher and 50 ° C. or lower higher than Tm1. Then, after cooling the sample to room temperature under the temperature lowering condition of 20 ° C./min for 10 minutes, the heat absorption peak when measured again under the temperature rising condition of 20 ° C./min was observed, and the temperature indicating the peak top was observed. Is the melting point of the liquid crystal polymer. As the measuring device, for example, DSC Q1000 manufactured by TA Instruments can be used.

<Graft-modified polyolefin (B)>
The graft-modified polyolefin is a resin in which the polyolefin is graft-modified and is not particularly limited as long as it is a resin having a polar group. Multiple types of modified polyolefins can also be used in combination.
Here, the polar group is a polar atomic group, and when this group is present in an organic compound, the compound is a polar group. Specific examples of polar groups that can be introduced into polyolefins by grafting include unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, fumaric acid, tetrahydrophthalic acid, itaconic acid, citraconic acid, crotonic acid, and isocrotonic acid. Derived carboxy groups; acid anhydride groups derived from derivatives of the aforementioned unsaturated carboxylic acids such as acid anhydrides, acid halides, amides, imides, and esters (eg, methyl (meth) acrylate and ethyl (meth) acrylate). Halocarbonyl group, carboxylic acid amide group, imide group, and carboxylic acid ester group; glycidyl methacrylate, glycidyl acrylate, monoglycidyl maleate, diglycidyl maleate, monoglycidyl itaconate, diglycidyl itaconate, monoglycidyl allyl succinate, allyl succil Diglycidyl acid, glycidyl p-styrene carboxylate, allyl glycidyl ether, methacryl glycidyl ether, styrene-p-glycidyl ether, p-glycidyl styrene, 3,4-epoxy-1-butene, 3,4-epoxy-3-methyl- Examples thereof include 1-butene and an epoxy group derived from an epoxy group-containing vinyl monomer such as vinylcyclohexene monooxide. Among these polar groups, it is easy to obtain a low-dielectric resin composition in a preferable phase state, and when the low-dielectric resin composition is used in contact with another material, the low-dielectric resin composition and the other material are used. It is preferable to contain an epoxy group because the adhesiveness of the resin is good.
The epoxy group can react with a functional group of the liquid crystal polymer (A) such as a phenolic hydroxyl group or a carboxy group. Therefore, the graft-modified polyolefin (B) having an epoxy group as a polar group and the liquid crystal polymer (A) have an appropriate affinity in the low-dielectric resin composition, facilitating a preferable phase structure such as a sea-island structure. Can be formed into.

Since the graft-modified polyolefin (B) has a polar group at a portion branched from the main chain, it exhibits an effect different from that of a polyolefin-based random copolymer or block copolymer. As will be shown in Examples and Comparative Examples described later, the low-dielectric resin composition containing a graft-modified polyolefin having a polar group is compared with the composition containing a polyolefin-based resin in which a monomer having a similar polar group is copolymerized. The dielectric loss tangent is significantly low. Further, since it is compatible with the liquid crystal polymer via the branch portion, it is not necessary to increase the amount of modification by the polar group. In general, the larger the amount of modification of a modified polyolefin due to a polar group, the lower the heat resistance. However, according to the graft-modified polyolefin (B), compatibility with the liquid crystal polymer is exhibited with a small amount of modification. Therefore, when the graft-modified polyolefin (B) is used, it is possible to impart good low-dielectric properties and melt processability to the low-dielectric resin composition without sacrificing heat resistance.

The amount of polar groups (modified amount) in the graft-modified polyolefin (B) is not particularly limited. Various modified amounts of the graft-modified polyolefin (B) can be used depending on the chemical structure of the liquid crystal polymer (A) and the intended use of the low-dielectric resin composition. However, the amount of the polar group-containing unit is 0.01% by mass or more and 5% by mass or less, and further 0.05 or more and 3% by mass or less, particularly 0.1% by mass or more 2 with respect to the entire graft-modified polyolefin (B). When it is mass% or less, good heat resistance and melt processability can be imparted to the low-dielectric resin composition, which is preferable. In particular, when the polar group is an epoxy group, the epoxy value of the graft-modified polyolefin (B) is preferably 0.01 to 5% by mass, more preferably 0.05% by mass or more and 3% by mass or less, and particularly preferably 0. .1 to 2% by mass is desirable.

Typically, the graft-modified polyolefin (B) is a resin in which the polyolefin is graft-modified with a vinyl monomer having a polar group in the presence of a radical polymerization initiator.
The graft-modified polyolefin (B) is preferably a polyolefin graft-modified with a vinyl monomer having a polar group and an aromatic vinyl monomer, and is graft-modified with glycidyl (meth) acrylate and styrene. More preferably, it is a polyolefin.

Examples of the polyolefin include polyethylene, polypropylene, poly-1-butene, polyisobutylene, polymethylpentene, propylene-ethylene copolymer, ethylene-propylene-diene copolymer, ethylene / butene-1 copolymer, and ethylene. / Chain polyolefins such as octene copolymers; cyclic polyolefins such as copolymers of cyclopentadiene with ethylene and / or propylene.

Among these polyolefins, polymethylpentene, polyethylene, polypropylene, and propylene-ethylene copolymers are preferable because the modification reaction is easy, and polymethylpentene is more preferable from the viewpoint of heat resistance and low dielectric properties.

Examples of radical polymerization initiators that can be used for graft modification of polyolefins include ketone peroxides such as methyl ethyl ketone peroxide and methyl acetoacetate peroxide; 1,1-bis (tert-butylperoxy) -3, 3,5-trimethylcyclohexane, 1,1-bis (tert-butylperoxy) cyclohexane, n-butyl-4,4-bis (tert-butylperoxy) valerate, and 2,2-bis (tert-butylperoxy). Oxy) Peroxyketal such as butane; hydroperoxides such as permethanehydroperoxide, 1,1,3,3-tetramethylbutylhydroperoxide, diisopropylbenzenehydroperoxide, and cumenehydroperoxide; dicumylper Oxide, 2,5-dimethyl-2,5-di (tert-butylperoxy) hexane, α, α'-bis (tert-butylperoxy-m-isopropyl) benzene, tert-butylcumyl peroxide, di- Dialkyl peroxides such as tert-butyl peroxide and 2,5-dimethyl-2,5-di (tert-butylperoxy) hexin-3; diacyl peroxides such as benzoyl peroxide; di (3-methyl-3). −methoxybutyl) peroxydicarbonate, and peroxydicarbonate such as di-2-methoxybutylperoxydicarbonate, tert-butylperoxyoctate, tert-butylperoxyisobutyrate, tert-butylperoxylau Rate, tert-butylperoxy-3,5,5-trimethylhexanoate, tert-butylperoxyisopropyl carbonate, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, tert-butylperoxy Examples thereof include acetate, tert-butylperoxybenzoate, and peroxyesters such as di-tert-butylperoxyisophthalate. The above radical polymerization initiator can be used alone or in combination of two or more.

The amount of the radical polymerization initiator used is not particularly limited as long as the graft modification reaction proceeds well. The amount of the radical polymerization initiator used is preferably 0.01 parts by mass or more and 10 parts by mass or less, and more preferably 0.2 parts by mass or more and 5 parts by mass or less with respect to 100 parts by mass of the polyolefin.

The vinyl monomer having a polar group that can be used for graft modification includes unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, fumaric acid, tetrahydrophthalic acid, itaconic acid, citraconic acid, crotonic acid, and isocrotonic acid. Acids; derivatives of these unsaturated carboxylic acids such as acid anhydrides, acid halides, amides, imides, and esters; glycidyl methacrylate, glycidyl acrylate, monoglycidyl maleate, diglycidyl maleate, monoglycidyl itaconate, itaconic acid. Diglycidyl, monoglycidyl allyl succinate, diglycidyl allyl succinate, glycidyl p-styrene carboxylate, allyl glycidyl ether, methacryl glycidyl ether, styrene-p-glycidyl ether, p-glycidyl styrene, 3,4-epoxy-1-butene, 3, Examples thereof include 4-epoxy-3-methyl-1-butene and epoxy group-containing vinyl monomers such as vinylcyclohexene monooxide.
Among these, an epoxy group-containing vinyl monomer is preferable, glycidyl methacrylate and glycidyl acrylate are more preferable, and glycidyl methacrylate is particularly preferable.
The vinyl monomer having the above polar groups can be used alone or in combination of two or more.

The amount of the vinyl monomer having a polar group used for the graft modification of the polyolefin is preferably 0.1 part by mass or more and 12 parts by mass or less, and 0.2 parts by mass or more and 10 parts by mass with respect to 100 parts by mass of the polyolefin. The amount is more preferably 0.3 parts by mass or more, and particularly preferably 0.3 parts by mass or more and 5 parts by mass or less.
By using a polyolefin modified with a vinyl monomer having a polar group in an amount within such a range, it is easy to obtain a low-dielectric resin composition which is in a preferable phase state and exhibits a desired low-dielectric property.

As described above, the graft-modified polyolefin (B) is preferably a vinyl monomer having a polar group and a polyolefin graft-modified with an aromatic vinyl monomer.
This is because the combined use of the vinyl monomer having a polar group and the aromatic vinyl monomer stabilizes the graft reaction, so that the vinyl monomer having a polar group can be easily grafted in a desired amount. ..

Specific examples of aromatic vinyl monomers include styrene; alkylstyrenes such as o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, β-methylstyrene, dimethylstyrene, and trimethylstyrene. Chlorostyrenes such as o-chlorostyrene, m-chlorostyrene, p-chlorostyrene, α-chlorostyrene, β-chlorostyrene, dichlorostyrene, and trichlorostyrene; o-bromostyrene, m-bromostyrene, p- Bromostyrenes such as bromostyrene, dibromostyrene, and tribromostyrene; fluorostyrenes such as o-fluorostyrene, m-fluorostyrene, p-fluorostyrene, difluorostyrene, and trifluorostyrene; o-nitrostyrene, m. Nitrostyrenes such as-nitrostyrene, p-nitrostyrene, dinitrostyrene, and trinitrostyrene; hydroxystyrenes such as o-hydroxystyrene, m-hydroxystyrene, p-hydroxystyrene, dihydroxystyrene, and trihydroxystyrene; Examples thereof include dialkenylbenzenes such as o-divinylbenzene, m-divinylbenzene, p-divinylbenzene, o-diisopropenylbenzene, m-diisopropenylbenzene, and p-diisopropenylbenzene.
Among these aromatic vinyl monomers, styrene, α-methylstyrene, p-methylstyrene, o-divinylbenzene, m-divinylbenzene, p-divinylbenzene, or a mixture of divinylbenzene isomers is preferable in terms of low cost. , Especially styrene is preferable.
The aromatic vinyl monomer can be used alone or in combination of two or more.

The amount of the aromatic vinyl monomer having a polar group used for the graft modification of the polyolefin is preferably 0.1 part by mass or more and 12 parts by mass or less, and 0.2 parts by mass or more and 10 parts by mass with respect to 100 parts by mass of the polyolefin. It is more preferably parts by mass or less, and particularly preferably 0.3 parts by mass or more and 5 parts by mass or less.

The low-dielectric resin composition described above is processed into various molded products by various known manufacturing methods such as injection molding, extrusion molding, and blow molding.
Since the low-dielectric resin composition described above is excellent in low-dielectric properties in the high-frequency band, it is preferably processed into a film, and the film is used to produce a flexible printed wiring board with low transmission loss.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

[Manufacturing Example 1]
(Manufacture of Modified Polyolefin 1)
(A1) 100 parts by mass of polymethylpentene resin (TPX grade MX002 manufactured by Mitsui Chemicals), (b1) 1.5 parts by mass of 1,3-di (tert-butylperoxyisopropyl) benzene (manufactured by NOF Corporation: Perbutyl P) , When supplying from the hopper mouth to a twin-screw extruder (46 mmφ, L / D = 63, manufactured by Kobe Steel) set to a cylinder temperature of 230 ° C. and a screw rotation speed of 150 rpm for melt kneading, from the middle of the cylinder ( c1) 8 parts by mass of styrene and (d1) 8 parts by mass of glycidyl methacrylate were added. Then, the modified polyolefin resin pellets were obtained by vacuum devolatile from the vent port.
After dissolving the obtained resin pellets in xylene at 130 ° C., using the recrystallized resin precipitated when cooled to room temperature again, glycidyl was used in a potential difference automatic titrator (AT700 manufactured by Kyoto Electronics Industry Co., Ltd.) in accordance with JIS K7236. The amount of methacrylate modification was measured. The amount of glycidyl methacrylate modification of the modified polyolefin 1 was 2.64% by mass.

[Production Examples 2 to 6]
(Manufacture of Modified Polyolefins 2 to 6)
Except that the addition amounts of (b1) 1,3-di (tert-butylperoxyisopropyl) benzene (manufactured by NOF: Perbutyl P), (c1) styrene, and (d1) glycidyl methacrylate were changed as follows. The same operation as in Production Example 1 was carried out to produce modified polyolefins 2 to 7. The amount of glycidyl methacrylate modification in each modified polyolefin was as follows.
-Modified polyolefin 2: (b1) 0.15 parts by mass, (c1) 0.5 parts by mass, (d1) 0.5 parts by mass: glycidyl methacrylate modification amount 0.23% by mass
-Modified polyolefin 3: (b1) 0.25 parts by mass, (c1) 1 part by mass, (d1) 1 part by mass: glycidyl methacrylate modification amount 0.35% by mass
-Modified polyolefin 4: (b1) 0.50 parts by mass, (c1) 2 parts by mass, (d1) 2 parts by mass: glycidyl methacrylate modified amount 0.74% by mass
-Modified polyolefin 5: (b1) 1.00 parts by mass, (c1) 4 parts by mass, (d1) 4 parts by mass: glycidyl methacrylate modification amount 1.56% by mass
-Modified polyolefin 6: (b1) 2.60 parts by mass, (c1) 12 parts by mass, (d1) 12 parts by mass: glycidyl methacrylate modified amount 4.29% by mass

[Examples 1 to 3 and Comparative Examples 1 to 6]
In Examples and Comparative Examples, a total aromatic liquid crystal polyester resin having a melting point of 280 ° C. was used as the liquid crystal polymers (A) (component (A)). Further, in the examples, the modified polyolefin 1 obtained in Production Example 1 was used as the graft-modified polyolefin (B) (component (B)).
In the comparative example, as a resin to be mixed with the liquid crystal polymer (A), unmodified polymethylpentene and an ethylene / glycidyl methacrylate / methyl acrylate copolymer (manufactured by Sumitomo Chemical Co., Ltd., Bond First 7L (BF-7L)) were used. Was used. Bond First 7L is a non-graft modified resin having 3% by mass of an epoxy group and 27% by mass of a methyl acrylate group as polar groups.

Each material in the amount shown in Table 1 is supplied from the hopper mouth to a twin-screw extruder (25 mmφ, L / D = 40, manufactured by Technobel) set to a cylinder temperature of 300 ° C. and a screw rotation speed of 150 rpm, and melt-kneaded. The resin compositions of Examples and Comparative Examples were obtained. In addition, Comparative Example 1 is an evaluation of the liquid crystal polymer (A) alone, and Comparative Example 4 is an evaluation of the modified polyolefin 1 alone. The relative permittivity, dielectric loss tangent, heat resistance, and processability of each Example and each Comparative Example resin or resin composition were evaluated according to the following methods. The results of these evaluations are shown in Table 1.

[Relative permittivity / dielectric loss tangent]
As a measuring device, a cavity resonator perturbation method complex dielectric constant evaluation device was used to measure the dielectric constant and the dielectric loss tangent of the resin composition obtained at the following frequencies.
Measurement frequency: 10GHz
Measurement conditions: temperature 22 ° C to 24 ° C, humidity 45% to 55%
Measurement sample: A sample left for 24 hours under the above measurement conditions was used.

[Heat-resistant]
As the measuring apparatus, using a dynamic viscoelasticity measuring device, the storage modulus was measured temperature (℃) reduced below 10 7 ^MPa. The measurement was performed under the following conditions, and the heat resistance was evaluated according to the following criteria.
-Sample measurement range: width 5 mm, distance between grippers 20 mm
-Measurement temperature range: 25 ° C to 260 ° C
・ Temperature rise rate: 5 ° C / min ・ Strain amplitude: 0.1%
・ Measurement frequency: 1Hz
-Minimum tension / compressive force; 0.1 g
・ Initial force amplitude; 100 g
Evaluation Criteria ◎: 260 ℃ but the storage modulus does not become less than ¹⁰ 7 MPa.
○: temperature storage modulus equal to or less than ¹⁰ 7 MPa is was 200 ° C. or higher.
×: temperature storage modulus equal to or less than ¹⁰ 7 MPa was less than 200 ° C..

[Melting (extrusion) workability]
The strands after melt-kneading using a twin-screw extruder (25 mmφ, L / D = 40, manufactured by Technobel) were water-cooled and the workability when cut by a pelletizer was evaluated as follows.
⊚: Columnar pellets can be obtained without cracking. ◯: Pellets with a flat shape are obtained with some cracking and chipping.
X: The strand cannot be cut and pellets cannot be obtained. Alternatively, most of the pellets contain whiskers and cracks.

[Film workability]
The processability when each of the pellets obtained above was formed into a film by T-die by melt extrusion was evaluated as follows.
⊚: No abnormality ◯: Resin lumps were generated on the lip portion of the T-die / or the film was sagging or tearing, but film formation was possible.
X: Resin lumps were generated on the lip portion of the T-die / or the film was sagging or tearing, and it was impossible to form a film.

[Phase structure]
The phase structure of the film composed of each low-dielectric resin composition was evaluated by observing with a scanning electron microscope by the following method.
(Cross section of film)
A range of 5 mm x 3 mm is cut out with a cutter knife, a protective film layer and a cover glass layer are formed on both sides of the cut out film using an epoxy-based embedding resin and a cover glass, and then cross-section polisher processing is performed with an ion beam. rice field.
(Cross section polisher processing)
Equipment used: SM-09020CP equivalent manufactured by JEOL Ltd. Processing conditions: Acceleration voltage 6kV.
(Observation of film cross section)
The cross section of the obtained film was observed with a scanning electron microscope.
(Scanning electron microscope observation)
Equipment used: Hitachi High-Technologies Corporation S-3000N equivalent Observation conditions: Acceleration voltage 15kV
Detector: Reflected electron detection (composition mode)
Magnification: 1000 times.
(Classification of observation results)
The observation results were classified according to the following criteria. The observation results are shown in Table 1.
A: Sea island structure ((A) component is the sea phase)
B: Sea-island structure ((A) component is island fauna)
C: Co-continuous structure (island fauna in a part of continuous area)
D: Phase separation

According to Examples, a composition containing a liquid crystal polymer (A) and a graft-modified polyolefin (B) having a polar group and having a sea phase formed on one of these components is good. It can be seen that excellent processability, particularly film processability, and excellent low-dielectric property can be achieved at the same time. In the low-dielectric resin compositions of these examples, the relative permittivity is 2.80 or less, which is lower than the value of the liquid crystal polymer (2.98: Comparative Example 1), and the dielectric loss tangent is 0.0025 or less, which is the modified polyolefin 1. It was lower than the value of (0.0056: Comparative Example 4). In the resin composition of the example, the size of each island phase was 5 μm or less.
On the other hand, in Comparative Example 5 in which the unmodified polyolefin was blended, the melt processability was poor and the film could not be processed into a film shape. In Comparative Example 6 in which Bond First 7L, which is a non-graft-modified polyolefin resin, was blended, a sea-island structure was formed and the workability was good, but the dielectric loss tangent became a large value.
Further, in Comparative Examples 2 and 3, both the liquid crystal polymer (A) and the modified polyolefin (B) had a co-continuous structure, and the film processing was performed as compared with the low-dielectric resin compositions of Examples 1 to 3 in which the sea-island structure was formed. The resin composition has inferior properties.

[Examples 4 to 38 and Comparative Examples 7 to 13]
From the above Examples and Comparative Examples, it was found that the processability of the resin composition was affected by the phase structure. Therefore, in order to further verify this point, modified polyolefins 2 to 7 were used in the same manner as in Example 1. The operation was performed. Table 2 shows the composition, melt processability, and phase structure of the resin composition in each example. For reference, the results of Examples 1 to 3 and Comparative Examples 2 and 3 are also shown.

From Table 2, the low-dielectric resin composition containing the liquid crystal polymer (A) and the graft-modified polyolefin (B) having a polar group and having a sea phase formed on one of the components is film-molded. It was shown to be excellent in sex.
Further, it was found that a low-dielectric resin composition containing a graft-modified polyolefin (B) having a modified amount of 2% by mass or less, particularly 1% by mass or less, easily forms a sea-island structure and is excellent in film moldability. ..

Some of the low-dielectric resin compositions of Examples 4 to 38 and Comparative Examples 7 to 12 were subjected to the same physical characteristic tests as in Example 1. The results are shown in Table 3.

According to Examples, if the composition contains a liquid crystal polymer (A) and a graft-modified polyolefin (B) having a polar group, and a sea phase is formed on one of the components, the polyolefin is used. It can be seen that good workability and excellent low-dielectric properties can be achieved at the same time regardless of the value of the modification amount. In the low-dielectric resin compositions of these examples, the relative permittivity was 2.80 or less, which was lower than the value of the liquid crystal polymer (2.98: Comparative Example 1). The dielectric loss tangent of the modified polyolefin 4 was measured (Comparative Example 13) and found to be 0.0027. It can be seen that in the low dielectric resin compositions of Examples 24 to 28 and 32 to 33, the dielectric loss tangent was 0.0025 or less, which was lower than that of the modified polyolefin 4. Moreover, in the resin composition of the example, the size of each island phase was 10 μm or less.

Claims (11)

A low-dielectric resin containing a liquid crystal polymer (A) and a graft-modified polyolefin (B) having a polar group, and having a sea-island structure in which discontinuous island phases are dispersed in a continuous sea phase. It ’s a composition,
A low-dielectric resin composition in which the sea phase in the sea-island structure is formed of either the liquid crystal polymer (A) or the graft-modified polyolefin (B) having a polar group, and the size of the island phase is 20 μm or less. thing. The relative permittivity at a frequency of 10 GHz is lower than the relative permittivity of the liquid crystal polymer (A) at a frequency of 10 GHz, and the dielectric loss tangent at a frequency of 10 GHz is at a frequency of 10 GHz of the graft-modified polyolefin (B) having the polar group. The low-dielectric resin composition according to claim 1, which has a value lower than the dielectric loss tangent. The low-dielectric resin composition according to claim 1 or 2, wherein the relative permittivity at a frequency of 10 GHz is 2.80 or less. The low dielectric resin composition according to any one of claims 1 to 3, wherein the dielectric loss tangent at a frequency of 10 GHz is 0.0025 or less. The low-dielectric resin composition according to any one of claims 1 to 4, further containing an olefin elastomer (C). The low-dielectric resin composition according to any one of claims 1 to 5, wherein the polar group is an epoxy group. The low-dielectric resin composition according to any one of claims 1 to 6, wherein the graft-modified polyolefin (B) is a polyolefin graft-modified with glycidyl (meth) acrylate and styrene. The method for producing a low-dielectric resin composition according to any one of claims 1 to 7, comprising a step of melt-kneading the liquid crystal polymer (A) and the graft-modified polyolefin (B) having the polar group. , A method for producing a low-dielectric resin composition. A molded product formed by using the low-dielectric resin composition according to any one of claims 1 to 7. A film formed by using the low-dielectric resin composition according to any one of claims 1 to 7. A flexible printed wiring board comprising the film according to claim 10.

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