JP2022067926A - Low dielectric resin composition, molded article, film, and flexible printed wiring board - Google Patents

Abstract

To provide a low dielectric resin composition which has good melt processability, is excellent in low dielectric characteristics, and especially exhibits a low dielectric loss tangent, a molded article and a film formed from the low dielectric resin composition, and a flexible printed wiring board including the above mentioned film.SOLUTION: A low dielectric resin composition contains graft-modified polyolefin (A), and a liquid crystal polymer (B), in which the low dielectric resin composition has a sea-island structure where an island phase as a discontinuous area is dispersed in a sea phase as a continuous area as a phase structure, and a graft copolymer of polyolefin and a vinyl monomer having an epoxy group is used as the graft-modified polyolefin (A).SELECTED DRAWING: Figure 1

Description

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

In recent years, communication devices such as smartphones and electronic devices such as next-generation televisions are 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, there is a demand for a low-dielectric material having a low relative permittivity and a dielectric loss tangent, which are factors related to the dielectric loss. Under these circumstances, for example, the use of a liquid crystal polymer as a low-dielectric material used in a high frequency band has been studied (see Patent Document 1).

Japanese Unexamined Patent Publication No. 2012-07717

However, a low-dielectric resin such as a liquid crystal polymer or a composition thereof is required to have further low-dielectric properties in order to further reduce the transmission loss.

Further, the liquid crystal polymer has a problem that melting processing is difficult 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 melted liquid crystal polymer discharged from the 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, the liquid crystal polymer has a problem that it is difficult to produce pellets by cutting the strands due to its anisotropy. 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. Non-uniformity of the shape of the pellets and whiskers on the pellets contribute to the instability of weighing the liquid crystal polymer during molding.

The present invention has been made in view of the above problems, and is a low-dielectric resin composition having good melt processability, excellent low-dielectric property, and particularly low dielectric loss tangent, and the low-dielectric resin composition. It is an object of the present invention to provide a molded product and a film made of the above-mentioned film, and a flexible printed wiring board including the above-mentioned film.

As a result of diligent studies to solve the above problems, the present inventors have completed the present invention.

That is, the present invention provides the following (1) to (11).
(1) Graft-modified polyolefin (A) and
Containing with liquid crystal polymer (B),
It has a sea-island structure in which island fauna, which is a discontinuous region, is dispersed in a sea phase, which is a continuous region, as a phase structure.
The sea phase consists of graft-modified polyolefin (A)
A low dielectric resin composition in which the graft-modified polyolefin (A) is a graft copolymer of a polyolefin and a vinyl monomer having an epoxy group.
(2) The dielectric loss tangent at a frequency of 10 GHz is lower than the dielectric loss tangent at a frequency of 10 GHz for the graft-modified polyolefin (A) alone, and the relative permittivity at a frequency of 10 GHz is the relative permittivity at a frequency of 10 GHz for the liquid crystal polymer (B) alone. The low dielectric resin composition according to (1), which has a value lower than the rate.
(3) The low-dielectric resin composition according to (1) or (2), wherein the relative permittivity at a frequency of 10 GHz is 2.60 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), wherein the graft-modified polyolefin (A) has a melting point of 200 ° C. or higher.
(6) The low dielectric resin composition according to any one of (1) to (5), wherein the graft-modified polyolefin (A) is a polyolefin graft-modified with glycidyl (meth) acrylate and styrene.
(7) The low-dielectric resin composition according to any one of (1) to (6), wherein the island phase has a size of 10 μm or less.
(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 graft-modified polyolefin (A) and the liquid crystal polymer (B). , A method for producing a low-dielectric resin composition.
(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, the present invention has been made in view of the above problems, and is a low-dielectric resin composition having good melt processability, excellent low-dielectric property, and particularly low dielectric loss tangent. It is possible to provide a molded product and a film made of the low-dielectric resin composition, and a flexible printed wiring board including the above-mentioned film.

It is a figure which shows the microscopic image which observed the phase structure of the composition obtained in Example 3. FIG. It is a figure which shows the microscopic image which observed the phase structure of the composition obtained in the comparative example 4.

≪Low dielectric resin composition≫
The low-dielectric resin composition is a resin composition containing a graft-modified polyolefin (A) and a liquid crystal polymer (B). The graft-modified polyolefin (A) is a graft copolymer of a polyolefin and a vinyl monomer having an epoxy group.
Further, the low-dielectric resin composition has a sea-island structure in which the island phase, which is a discontinuous region, is dispersed in the sea phase, which is a continuous region, as a phase structure. In the sea island structure, the sea phase is composed of the graft-modified polyolefin (A).

The above low dielectric resin composition contains a graft-modified polyolefin (A) as a sea phase. Therefore, at the time of melt processing, the properties of the graft-modified polyolefin (A), which is the sea phase, dominate, and the content of the graft-modified polyolefin (A) in the low-dielectric resin composition is the content of the liquid crystal polymer (B). Even if it is less than that, it shows excellent melt processability.

The dielectric loss tangent at 10 GHz of the low dielectric resin composition is preferably lower than the dielectric loss tangent at a frequency of 10 GHz for the graft-modified polyolefin (A) alone. The relative permittivity of the low-dielectric resin composition at 10 GHz is preferably lower than the relative permittivity of the liquid crystal polymer (B) alone at a frequency of 10 GHz.
The dielectric loss tangent of the low dielectric resin composition at 10 GHz is preferably 0.0025 or less. The lower limit of the dielectric loss tangent described above is not particularly limited. The lower limit of the dielectric loss tangent may be, for example, 0.0005 or more, and may be 0.0010 or more.

The relative permittivity of the above low-dielectric resin composition at a frequency of 10 GHz is preferably 2.60 or less. The lower limit of the above-mentioned relative permittivity is not particularly limited. The lower limit of the relative permittivity may be, for example, 2.00 or more, or 2.10 or more.

The above-mentioned low-dielectric resin composition makes use of its low-dielectric property, and 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.

The resin composition containing the graft-modified polyolefin (A) and the liquid crystal polymer (B) includes the mixing ratio of the graft-modified polyolefin (A) and the liquid crystal polymer (B), the melting point of the graft-modified polyolefin (A), and the liquid crystal polymer. The melting point of (B), the difference between the melting point of the graft-modified polyolefin (A) and the melting point of the liquid crystal polymer (B), the temperature at which the graft-modified polyolefin (A) and the liquid crystal polymer (B) are mixed, and the graft-modified polyolefin ( Various phase states can be formed depending on various conditions such as the amount of modification of A).
By adjusting the above-mentioned various conditions, the phase structure of the low-dielectric resin composition can be changed to a phase structure in which the graft-modified polyolefin (A) is a sea phase.

Among the above conditions, the mixing ratio of the graft-modified polyolefin (A) and the liquid crystal polymer (B) and the amount of modification of the graft-modified polyolefin (A) have a large effect on the phase structure of the low-dielectric resin composition. ..
As a general tendency, the larger the content of the graft-modified polyolefin (A) in the low-dielectric resin composition, the easier it is to form a sea-island structure having a sea phase composed of the graft-modified polyolefin (A). Further, the lower the amount of modification of the graft-modified polyolefin (A) by the vinyl monomer having an epoxy group, the smaller the content of the graft-modified polyolefin (A) in the low-dielectric resin composition, the more the graft-modified polyolefin (A). ) Is likely to form a sea-island structure with a sea phase.

For example, when the amount of modification of the graft-modified polyolefin (A) by the vinyl monomer having an epoxy group is about 0.5% by mass or more and 1.0% by mass or less, the mass of the graft-modified polyolefin (A) and the liquid crystal polymer. The ratio of the mass of the graft-modified polyolefin (A) to the total mass of (B) is preferably about 25% by mass or more and 75% by mass or less.
When the amount of modification of the graft-modified polyolefin (A) by the vinyl monomer having a poxy group is about 2.0% by mass or more and 3.0% by mass or less, the mass of the graft-modified polyolefin (A) and the liquid crystal polymer. The ratio of the mass of the graft-modified polyolefin (A) to the total mass of (B) is preferably about 40% by mass or more and 80% by mass or less.

Here, the fact that the sea-island structure is formed in the low-dielectric resin composition means that when the cross section of the sample of the low-dielectric resin composition is observed using an electron microscope (SEM), the size is arbitrary of 100 μm × 100 μm. It means that the sea-island structure is observed in at least one of the three observation target areas.
In the phase state of the sea-island structure, the anisotropy derived from the properties of the liquid crystal polymer (B) is alleviated, and the melt processability of the low-dielectric resin composition is good.

The fact that the graft-modified polyolefin (A) forms a continuous phase means that when the cross section of the sample of the low dielectric resin composition is observed using an electron microscope (SEM), the graft-modified polyolefin (A) has an outer periphery in the field of view. Says that forms an unclosed area.

The low-dielectric resin composition is produced by mixing a graft-modified polyolefin (A) and a liquid crystal polymer (B).
The method of mixing the graft-modified polyolefin (A) and the liquid crystal polymer (B) is not particularly limited. As a preferable mixing method, a method using a melt-kneading device such as a single-screw extruder or a twin-screw extruder can be mentioned.
The condition for mixing the graft-modified polyolefin (A) and the liquid crystal polymer (B) is that the graft-modified polyolefin (A) and the liquid crystal polymer (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 excessively thermally decompose or sublimate. When a melt-kneading device is used, for example, a temperature higher than the melting point of the graft-modified polyolefin (A) and the melting point of the liquid crystal polymer (B), preferably 5 ° C. or higher and 100 ° C. or lower, more preferably. Is melt-kneaded at a high temperature of 10 ° C. or higher and 50 ° C. or lower.

The low-dielectric resin composition may contain other resins other than the graft-modified polyolefin (A) and the liquid crystal polymer (B) as long as the object of the present invention is not impaired. The total ratio of the mass of the liquid crystal polymer (B) and the mass of the graft-modified polyolefin (A) to the total mass of the resin component contained in the low dielectric resin composition is typically 80% by mass, preferably 90. 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.
Further, as an example of other resins, various elastomers may also be preferably used. Examples of the elastomer include polyolefin elastomers, polyamide elastomers, polyurethane elastomers, polyester elastomers and the like.
It has excellent compatibility with the graft-modified polyolefin (A), is easily compatible with the sea phase composed of the graft-modified polyolefin (A) in the low-dielectric resin composition, and easily imparts appropriate flexibility to the low-dielectric resin composition. Among the above-mentioned elastomers, polyolefin elastomers are preferable because it is easy to obtain a low-dielectric resin composition having excellent low-dielectric properties.

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 fiber, milled glass fiber, carbon fiber, alumina fiber, silica alumina fiber, 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 use 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 needed. 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 graft-modified polyolefin (A) and the liquid crystal polymer (B) will be described.

<Graft-modified polyolefin (A)>
The graft-modified polyolefin (A) is a resin in which the polyolefin is graft-modified with a vinyl monomer having an epoxy group. Therefore, the graft-modified polyolefin (A) has an epoxy group as a polar group.
The epoxy group can react with a functional group of the liquid crystal polymer (B) such as a phenolic hydroxyl group or a carboxy group. Therefore, the graft-modified polyolefin (A) having an epoxy group as a polar group and the liquid crystal polymer (B) have an appropriate affinity in the low-dielectric resin composition, and a sea-island structure can be easily formed.

The diameter of the island in the sea-island structure is preferably 100 μm or less, more preferably 50 μm or less, still more preferably 10 μm or less. The lower limit of the diameter of the island is not particularly limited, but may be, for example, 1 μm or more, 2 μm or more, or 3 μm or more.
With the miniaturization and thinning of various electric and electronic devices, the film applied to such devices may be required to have a thinness of, for example, 100 μm or less. Considering that the thickness of the film formed by using the low-dielectric resin composition is often 100 μm or less, it is possible to suppress the variation in the characteristics of the film while obtaining the effect of the sea-island structure of the layer structure. In terms of points, the diameter of the island is preferably in the range of 1 μm or more and 100 μm or less.
In addition, "the diameter of the island is X μm or less" means that the size of the island fauna that is 90% or more, usually 95% or more, typically 99% or more of the whole island fauna that is a discontinuous region is X μm or less. Is shown. Further, "island diameter of Y μm or more" means that the size of the island fauna that is 90% or more, usually 95% or more, typically 99% or more of the whole island fauna that is a discontinuous region is X μm or more. Is shown.
Here, the "diameter" generally refers to the diameter of the island. When the shape of the island is significantly different from the circular shape, the major axis (the length of the long side of the rectangle circumscribing the island) is defined as the "diameter". Here, the major axis is the length of the long side of the rectangle circumscribing the island, or the length of one side of the square circumscribing the island.
As a method of confirming the diameter of the island, for example, a film formed by using a low dielectric resin composition as in the examples described later is embedded in a thermosetting resin, and a cross section in the thickness direction is formed by an ion beam. A method of polishing to expose the cross section of the film and observing the cross section of the film with a scanning electron microscope can be mentioned.

The amount of modification of the graft-modified polyolefin (A) having an epoxy group by the vinyl monomer having an epoxy group is preferably 10% by mass or less, more preferably 5% by mass or less, still more preferably 1% by mass or less. The lower limit of the amount of modification by the vinyl monomer having an epoxy group described above is not particularly limited as long as it does not impair the object of the present invention. The lower limit may be, for example, 0.1% by mass or more, 0.3% by mass or more, or 0.5% by mass or more.
When the amount of modification of the graft-modified polyolefin (A) having an epoxy group by the vinyl monomer having an epoxy group is 0.1% by mass or more and 10% by mass or less, the processability by using the graft-modified polyolefin (A) is possible. It is particularly easy to obtain a low-dielectric resin composition having excellent low-dielectric properties.
The amount of modification by the vinyl monomer having an epoxy group can be measured by using a potential difference automatic titrator (AT700 manufactured by Kyoto Denshi Kogyo Co., Ltd.) in accordance with JIS K7236. A graft-modified polyolefin (A) recrystallized from xylene can be used for measuring the amount of modification with the vinyl monomer having an epoxy group.

Typically, the graft-modified polyolefin (A) is a resin in which the polyolefin is graft-modified with a vinyl monomer having an epoxy group in the presence of a radical polymerization initiator.
The graft-modified polyolefin may be graft-modified with a vinyl monomer having an epoxy group and a vinyl monomer other than the vinyl monomer having an epoxy group.
The graft-modified polyolefin (A) is preferably a vinyl monomer having an epoxy group and a polyolefin graft-modified with 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 can be mentioned.

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). -Methylbutyl) 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 peroxy esters such as acetate, tert-butyl peroxybenzoate, and di-tert-butyl peroxyisophthalate. The above radical polymerization initiator may 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.

Examples of the vinyl monomer having an epoxy group that can be used for graft modification include glycidyl methacrylate, glycidyl acrylate, monoglycidyl maleate, diglycidyl maleate, monoglycidyl itaconate, diglycidyl itaconate, monoglycidyl allyl succinate, and allyl succinic acid. Diglycidyl, p-styrene carboxylate glycidyl, allyl glycidyl ether, methacrylic glycidyl ether, styrene-p-glycidyl ether, p-glycidyl styrene, 3,4-epoxide-1-butene, 3,4-epoxide-3-methyl-1 -Epoxide-containing vinyl monomers such as butene and vinylcyclohexene monooxide can be mentioned.
Among these, glycidyl methacrylate and glycidyl acrylate are more preferable, and glycidyl methacrylate is particularly preferable.
The vinyl monomer having an epoxy group described above can be used alone or in combination of two or more.

Examples of the vinyl monomer that can be used together with the vinyl monomer having an epoxy group include acrylic acid, methacrylic acid, maleic acid, fumaric acid, tetrahydrophthalic acid, itaconic acid, citraconic acid, crotonic acid, and isocrotonic acid. Unsaturated carboxylic acids; include derivatives of these unsaturated carboxylic acids such as acid anhydrides, acid halides, amides, imides, and esters.

The amount of the vinyl monomer having an epoxy 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 0.5 parts by mass or more and 10 parts by mass with respect to 100 parts by mass of the polyolefin. It is more preferably 1 part by mass or less, and particularly preferably 1 part by mass or more and 8 parts by mass or less.
By using the modified polyolefin (A) modified with a vinyl monomer having an epoxy group in an amount within such a range, a low-dielectric resin composition having a preferable phase state and exhibiting desired low-dielectric properties can be obtained. Cheap.

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

Specific examples of aromatic vinyl monomers include styrene; alkyl styrenes such as o-methyl styrene, m-methyl styrene, p-methyl styrene, α-methyl styrene, β-methyl styrene, dimethyl styrene, and trimethyl styrene. 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. , Particularly styrene is preferred.
The aromatic vinyl monomer can be used alone or in combination of two or more.

The amount of the aromatic vinyl monomer having an epoxy 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 0.5 parts by mass or more and 10 parts by mass with respect to 100 parts by mass of the polyolefin. It is more preferably 1 part by mass or less, and particularly preferably 1 part by mass or more and 8 parts by mass or less.

Since melt-kneading with the liquid crystal polymer (B) is easy, the melting point of the graft-modified polyolefin (A) is preferably 80 ° C. or higher, more preferably 100 ° C. or higher, and even more preferably 200 ° C. or higher. The upper limit of the melting point of the graft-modified polyolefin (B) is not particularly limited, but is preferably 350 ° C. or lower, more preferably 300 ° C. or lower.

<Liquid crystal polymer (B)>
The liquid crystal polymer (B) 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 polarizing element.

The liquid crystal polymer (B) 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.

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 a 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.

The structural units constituting the liquid crystal polymer (B) include aromatic oxycarbonyl units, aromatic dicarbonyl units, aromatic dioxy units, aromatic aminooxy units, aromatic diamino units, aromatic aminocarbonyl units, and aliphatics. Examples include dioxy units.
The liquid crystal polymer (B) may contain an amide bond or a thioester bond as a bond other than the ester bond.

The aromatic oxycarbonyl unit is a unit derived from an aromatic hydroxycarboxylic acid.
Suitable specific examples of aromatic hydroxycarboxylic acids 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-forming derivatives such as ester derivatives of aromatic hydroxycarboxylic acids and acid halides can also be suitably 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 (B) can be easily prepared.

The aromatic dicarbonyl repeating unit is a unit derived from an aromatic dicarboxylic acid.
Suitable specific examples of aromatic dicarboxylic acids 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-forming derivatives such as an ester derivative of an aromatic dicarboxylic acid and an acid halide can also be preferably used in the same manner as the aromatic dicarboxylic acid.
Among these aromatic dicarboxylic acids, terephthalic acid and 2,6-naphthalenedicarboxylic acid are included because it is easy to adjust the mechanical properties, heat resistance, melting point temperature, and moldability of the obtained liquid crystal polymer (B) to appropriate levels. preferable.

The aromatic dioxy repeating unit is a unit derived from an aromatic diol.
Suitable specific examples of aromatic diols include hydroquinone, resorcin, 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-substituted products 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 and the characteristics of the obtained liquid crystal polymer (B).

Aromatic aminooxy units are units derived from aromatic hydroxyamines.
Suitable specific examples of aromatic hydroxyamines are 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.
Suitable specific examples of aromatic diamines 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.

The aromatic aminocarbonyl unit is a unit derived from an aromatic aminocarboxylic acid.
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 the liquid crystal polymer (B).

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 acylated products thereof.
Further, 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 thereof, an ester derivative, or an acid halogen. A liquid crystal polymer (B) containing an aliphatic dioxy unit can also be obtained by reacting with a compound or the like.

The liquid crystal polymer (B) may contain a thioester bond. Examples of the monomer giving such a bond include mercapto aromatic carboxylic acid, aromatic dithiol, hydroxy aromatic thiol and the like.
The amount of these monomers used is aromatic oxycarbonyl repeating unit, aromatic dicarbonyl repeating unit, aromatic dioxy repeating unit, aromatic aminooxy repeating unit, aromatic diamino repeating unit, aromatic aminocarbonyl repeating unit, It is preferably 10 mol% or less with respect to 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 (B) include the following 1) to 25).
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-naphthoic 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.

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 standpoint 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 to obtain a monomer mixture containing an acylated product of a monomer having a phenolic hydroxyl group.

The liquid crystal polymer (B) is 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 the liquid crystal polymer (B) 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 the liquid crystal polymer (B) 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 the liquid crystal polymer (B) 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.
The liquid crystal polymer (B) produced by the above method may be subjected to polycondensation by heating in a solidified state (solid phase), if necessary, in order to further increase the molecular weight.

The liquid crystal polymer (B) is obtained by the above method. The melting point of the liquid crystal polymer (B) 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 (B) is preferably 250 ° C. or higher, more preferably 280 ° C. or higher. On the other hand, the melting point of the liquid crystal polymer (B) 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 (A) during the production of the low-dielectric resin composition. More preferred.
The melting point of the liquid crystal polymer (B) is, for example, the temperature obtained from the crystal melting peak measured at a heating rate of 20 ° C./min by a differential scanning calorimeter (hereinafter abbreviated as DSC). .. More specifically, after observing the heat absorption peak temperature (Tm1) observed when the sample of the liquid crystal polymer (B) is measured at a temperature rising condition of 20 ° C./min from room temperature, the temperature is 20 ° C. or higher and 50 ° C. from Tm1. After holding the sample at a high temperature for 10 minutes and then cooling the sample to room temperature under a temperature decrease condition of 20 ° C./min, the heat absorption peak was observed again when measured under a temperature rise condition of 20 ° C./min, and the peak top was observed. Let the temperature indicating the above be the melting point of the liquid crystal polymer (B). As the measuring device, for example, DSC Q1000 manufactured by TA Instruments can be used.
Further, it is possible to use two or more kinds of the liquid crystal polymer (B) as long as the object of the present invention is not impaired.
The above-mentioned graft-modified polyolefin (A) having an epoxy group easily disperses well with the liquid crystal polymer (B). Therefore, even if two or more kinds of liquid crystal polymers (B) having different kinds are used, the graft-modified polyolefin (A) and the liquid crystal polymer (B) are easily dispersed well to form a preferable phase state.
Further, when two or more kinds of liquid crystal polymers (B) are used, the liquid crystal polymer (B) having a melting point of less than 300 ° C. and the liquid crystal polymer (B) having a melting point of 300 ° C. or more are excellent in a good balance between processability and heat resistance. It is preferable to use in combination with.
When two types of liquid crystal polymers (B) are used, the difference in melting point between the two types of liquid crystal polymers (B) is preferably 5 ° C. or higher and 50 ° C. or lower, for example.

The low dielectric resin composition described above is processed into various molded products by various known manufacturing methods such as injection molding, extrusion molding, blow molding, and solution casting method.
Since the low-dielectric resin composition described above has excellent 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.

Suitable methods for producing a film using the low-dielectric resin composition include the following methods 1) and 2).
1) Melt extrusion method using T-die.
2) Solution casting method.
In the solution casting method, specifically, an organic solvent solution of a low-dielectric resin composition is cast on a support, and then the organic solvent is removed from the cast organic solvent solution by a method such as heating and / or depressurization. A film is obtained.
The casting method is not particularly limited, and examples thereof include known methods such as a die coater, a comma coater (registered trademark), a reverse coater, and a knife coater. Heating is preferable as a method for removing the organic solvent. Examples of the heating method include a method using a known heating device such as a hot air furnace or a far-infrared furnace.
The organic solvent solution of the low-dielectric resin composition can be obtained, for example, by mixing the low-dielectric resin composition and xylene at a temperature of about 80 ° C. Instead of the low-dielectric resin composition, two or more kinds of materials constituting the low-dielectric resin composition may be mixed with xylene.

The thickness of the film made of the low-dielectric resin composition is not particularly limited, and is appropriately determined depending on the use of the film. When a flexible printed wiring board is manufactured using a film, the thickness of the film is preferably 5 μm or more and 200 μm or less, and more preferably 10 μm or more and 100 μm or less.

More specifically, the flexible printed wiring board typically forms a wiring by etching a metal foil in a laminated film in which a film made of the above-mentioned low dielectric resin composition and a metal foil are laminated. Manufactured by.
Since such a flexible printed wiring board has a high transmission speed and a small transmission loss, it is suitably used as a circuit board applied to high frequency applications.

Examples of the method for obtaining a laminated film in which a film made of a low-dielectric resin composition and a metal foil are laminated include the following methods I) and II).
I) A method of obtaining a laminated film by thermocompression bonding a film made of a low-dielectric resin composition and a metal foil by heating and pressurizing.
II) A method in which an organic solvent solution of a low dielectric resin composition is cast on a metal foil, and the organic solvent is removed from the cast organic solvent solution by a method such as heating and / or depressurization to obtain a laminated film.
In the method I), the method and conditions for thermocompression bonding the film made of the low-dielectric resin composition and the metal foil by heating and pressurizing are appropriately selected from the conventionally known methods and conditions. Since the low dielectric resin composition contains the graft-modified polyolefin (A) having a melting point having a low melting point to some extent, thermocompression bonding is performed while maintaining the peel strength when peeling the metal foil from the film at a high strength of 5 N / cm or more. The temperature can be set low. The thermocompression bonding temperature is preferably 400 ° C. or lower, more preferably 200 ° C. or lower.
The method of laminating the film on the metal foil in the method II) is the same as the method described above as the solution casting method except that the metal foil is used as a support.
In the laminated film, the metal foil may be laminated on at least one main surface of the film, and even if the metal foil is laminated only on one main surface of the film, the metal foil is laminated on both main surfaces of the film. It may be laminated.

The metal foil attached to the film made of the low-dielectric resin composition is not particularly limited. Metal foil materials used in the manufacture of flexible printed wiring boards used in electrical and electronic equipment applications include copper, copper alloys, nickel, nickel alloys (eg 42 alloys), aluminum, aluminum alloys, and stainless steel. Steel is mentioned.
Copper foil is preferable as the metal foil used when manufacturing a flexible printed wiring board because it has excellent conductivity and processability and has high bonding strength with a film. As the copper foil, for example, rolled copper foil, electrolytic copper foil and the like are preferably used.
If necessary, a functional layer such as a rust preventive layer, a heat-resistant layer, and an adhesive layer may be provided on the surface of the metal foil described above.
The thickness of the metal foil is not particularly limited, and is appropriately selected depending on the application of the flexible printed wiring board.

With respect to the laminated film in which the film made of the low dielectric resin composition and the metal foil are laminated, the peel strength, which is an index of the resistance of the metal foil to peeling from the film, is preferably 5 N / cm or more.
The peel strength can be measured according to "6.5 Peeling strength" of JIS C 6471. Specifically, by peeling the metal foil portion having a width of 1 mm under the conditions of a peeling angle of 90 ° and a speed of 100 mm / min, the weight at the time of peeling can be measured as the peel strength.

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]
(Manufacturing 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) , From the middle of the cylinder when supplying to a twin-screw extruder (46 mmφ, L / D = 63, manufactured by Kobe Steel Co., Ltd.) set to a cylinder temperature of 230 ° C and a screw rotation speed of 150 rpm from the hopper mouth. 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 denaturation was measured. The amount of glycidyl methacrylate modification of the modified polyolefin 1 was 2.64% by mass.

[Manufacturing Example 2]
(Manufacturing of Modified Polyolefin 2)
(A1) 100 parts by mass of polymethylpentene resin (TPX grade MX002 manufactured by Mitsui Chemicals), (b1) 0.5 parts by mass of 1,3-di (t-butylperoxyisopropyl) benzene (manufactured by NOF Corporation: Perbutyl P) , From the middle of the cylinder when supplying to a twin-screw extruder (46 mmφ, L / D = 63, manufactured by Kobe Steel Co., Ltd.) set to a cylinder temperature of 230 ° C and a screw rotation speed of 150 rpm from the hopper mouth. c1) 2 parts by mass of styrene and (d1) 2 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 denaturation was measured. The amount of glycidyl methacrylate modification of the modified polyolefin 2 was 0.74% by mass.

[Manufacturing Example 3]
(Manufacturing of Modified Polyolefin 3)
(A1) 100 parts by mass of polymethylpentene resin (TPX grade MX002 manufactured by Mitsui Chemicals), (b1) 0.25 parts by mass of 1,3-di (t-butylperoxyisopropyl) benzene (manufactured by NOF Corporation: Perbutyl P) , From the middle of the cylinder when supplying to a twin-screw extruder (46 mmφ, L / D = 63, manufactured by Kobe Steel Co., Ltd.) set to a cylinder temperature of 230 ° C and a screw rotation speed of 150 rpm from the hopper mouth. c1) 1 part by mass of styrene and (d1) 1 part 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 denaturation was measured. The amount of glycidyl methacrylate modification of the modified polyolefin 3 was 0.35% by mass.

[Manufacturing Example 4]
(Manufacturing of Modified Polyolefin 4 (Modified Polypropylene))
(A1) 100 parts by mass of polypropylene (polypropylene grade J106G made of prime polymer), (b1) 0.25 parts by mass of 1,3-di (tert-butylperoxyisopropyl) benzene (manufactured by Nichiyu: Perbutyl P), hopper mouth Therefore, when supplying to the same twin-screw extruder as in Production Example 1 in which the cylinder temperature is set to 200 ° C. and the screw rotation speed is set to 150 rpm to perform melt kneading, 2.5 parts by mass of (c1) styrene and (d1) are formed from the middle of the cylinder. 2.5 parts by mass of glycidyl methacrylate was added. Then, the modified polyolefin resin pellets were obtained by vacuum devolatile from the vent port. When the amount of modification was measured in the same manner as in Production Example 1, the amount of glycidyl methacrylate modification of the modified polyolefin 4 was 1.1% by mass.

[Examples 1 to 8 and Comparative Examples 1 to 9]
In Examples and Comparative Examples, as the liquid crystal polymers (B) (component (B)), a fully aromatic liquid crystal polyester resin (B-1) having a melting point of 280 ° C. and a fully aromatic liquid crystal polyester resin (B-) having a melting point of 320 ° C. 2) was used. Further, in the examples, the modified polyolefins 1 to 4 obtained in Production Examples 1 to 4 were used as the graft-modified polyolefins (A) (component (A)). The melting point of the modified polyolefins 1 to 3 is about 230 ° C. The melting point of the modified polyolefin 4 is about 160 ° C.
In the comparative example, as the resin to be mixed with the liquid crystal polymer (B), modified polyolefin 1, modified polyolefin 2, unmodified polymethylpentene, and ethylene / glycidyl methacrylate / methyl acrylate copolymer (manufactured by Sumitomo Chemical Co., Ltd.) Bond First 7L (BF-7L)) was used. Bond First 7L is a non-graft modified resin having an epoxy group.

A twin-screw extruder (25 mmφ, L / D =) in which the amounts of each material shown in Table 1 or 2 were set at a cylinder temperature of 300 ° C. (340 ° C. in Examples 6 and 7) and a screw rotation speed of 150 rpm from the hopper port. 40, manufactured by Technobel) and melt-kneaded to obtain resin compositions of Examples and Comparative Examples. In addition, about Comparative Examples 1, 2, 3, and 8, the evaluation is based on the modified polyolefin 1, the modified polyolefin 2, the liquid crystal polymer (B), or Bond First 7L alone. The relative permittivity, dielectric loss tangent, processability, and film 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 Tables 1 and 2.

[Relative permittivity / dielectric loss tangent]
As a measuring device, a cavity resonator perturbation method complex permittivity evaluation device was used to measure the permittivity and 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.

[Workability]
The strands after melt-kneading using a twin-screw extruder (25 mmφ, L / D = 40, manufactured by Technobel) were water-cooled, and the processability when cut by a pelletizer was evaluated as follows.
◯: Columnar pellets can be obtained without cracking.
Δ: A part of cracks and chips is included, and the pellet has a flat shape.
X: Strands cannot be cut and pellets cannot be obtained. Or most of the pellets contain whiskers and cracks.

[Film workability]
The resin compositions or resins of each Example and Comparative Example were melted at 250 ° C., and the melted resin composition was extruded from a 140 mm wide T-die to a thickness of approximately 100 μm to obtain a film.
In Comparative Example 3, the liquid crystal polymer (component (B)) was melted at 300 ° C. to obtain a film.
The processability at the time of film processing by the above method was evaluated as follows.
○: No abnormality.
Δ: Resin lumps (rheum) are generated on the lip of the T-die, but film molding is possible.
X: Resin lumps (rheum) are generated on the lip of the T-die, and film molding is not possible.

[Phase structure]
The phase structure of each composition was confirmed by microscopic observation. The observation results were classified according to the following criteria. The observation results are shown in Tables 1 and 2. Further, microscopic images of the composition of Example 3 and the composition of Comparative Example 4 in which the phase structures are observed are shown in FIGS. 1 and 2, respectively. The arrows in the figure indicate the resin flow direction (MD direction).
In Examples 1 to 8, the observation results were all A, and the size of the island phase measured by the above method was 10 μm or less.
A: Sea island structure ((A) component is the sea)
B: Sea island structure ((A) component is an island)
C: Partial sea island structure and co-continuous structure D: Phase separation

According to the examples, any resin composition having a sea-island structure containing a graft-modified polyolefin (A) having an epoxy group and a liquid crystal polymer (B) and containing a sea phase composed of the graft-modified polyolefin (A). It can be seen that both good low dielectric properties and excellent melt processability can be achieved.
On the other hand, according to a comparative example, a graft-modified polyolefin (A) having an epoxy group, a liquid crystal polymer (B), or a non-grafted resin having an epoxy group can be used alone, or a graft-modified polyolefin having an epoxy group (A). ) And the liquid crystal polymer (B), but do not have a sea-island structure containing a sea phase composed of the graft-modified polyolefin (A), or the liquid crystal polymer (B) is blended with an unmodified polyolefin. It can be seen that in the loose resin composition, at least one of the low dielectric property and the melt processability is inferior.

Further, the graft-modified polyolefin (A) having an epoxy group disperses well with each other when melt-kneaded with the liquid crystal polymer (B). Therefore, as can be seen from Examples 6 and 7, even when a plurality of types of liquid crystal polymers (B) having different melting points are used, the graft-modified polyolefin (A) is a sea phase and the liquid crystal polymer (B) is an island. It is possible to realize a preferable phase structure which is a phase. As a result, it is easy to blend the liquid crystal polymer (B) having a high melting point into the low-dielectric resin composition, and by using a plurality of types of liquid crystal polymers (B) having different melting points, it is easy to obtain a low-dielectric resin composition having excellent heat resistance. ..

Claims (11)

With graft-modified polyolefin (A),
Containing with liquid crystal polymer (B),
It has a sea-island structure in which island fauna, which is a discontinuous region, is dispersed in a sea phase, which is a continuous region, as a phase structure.
The sea phase is composed of the graft-modified polyolefin (A).
A low-dielectric resin composition in which the graft-modified polyolefin (A) is a graft copolymer of a polyolefin and a vinyl monomer having an epoxy group. The dielectric loss tangent at a frequency of 10 GHz is lower than the dielectric loss tangent at a frequency of 10 GHz for the graft-modified polyolefin (A) alone, and the relative permittivity at a frequency of 10 GHz is the relative permittivity at a frequency of 10 GHz for the liquid crystal polymer (B) alone. The low dielectric resin composition according to claim 1, which has a lower value than. The low-dielectric resin composition according to claim 1 or 2, wherein the relative permittivity at a frequency of 10 GHz is 2.60 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, wherein the graft-modified polyolefin (A) has a melting point of 200 ° C. or higher. The low dielectric resin composition according to any one of claims 1 to 5, wherein the graft-modified polyolefin (A) is a polyolefin graft-modified with glycidyl (meth) acrylate and styrene. The low-dielectric resin composition according to any one of claims 1 to 6, wherein the island phase has a size of 10 μm or less. The method for producing a low-dielectric resin composition according to any one of claims 1 to 7, which comprises a step of melt-kneading the base graft-modified polyolefin (A) and the liquid crystal polymer (B). A method for producing a 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.

Images