JP2023140301A - Polycarbonate resin composition - Google Patents

Abstract

To provide a polycarbonate resin composition having a low relative permittivity and a low dielectric loss tangent and excelling in terms of heat resistance, impact resistance, toughness, and rigidity.SOLUTION: A polycarbonate resin composition comprises 100 pts.mass of a polycarbonate resin (A), 30-150 pts.mass of a polystyrene resin (B), and 3-60 pts.mass of an elastomer (C). The ratio in melt viscosity between the polycarbonate resin (A) and the polystyrene resin (B), ηA/ηB, at 260°C and 1,216 sec-1 ranges from 4.5 to 12.5.SELECTED DRAWING: None

Description

The present invention relates to a polycarbonate resin composition, and more particularly, to a polycarbonate resin composition that has low dielectric constant and dielectric loss tangent, and has excellent heat resistance, impact resistance, toughness, and rigidity.

2. Description of the Related Art Signals used in mobile communication devices, their base station devices, network infrastructure devices such as servers and routers, and electronic devices such as large computers are becoming faster and larger. In addition to the above-mentioned electronic devices, systems that handle high-frequency radio signals are being put into practical use in the fields of automobiles, transportation systems, and indoor short-range communications.

In the field of information and communication using high-frequency signals at the GHz level, there is a remarkable increase in speed, and commercial services for the 5th generation mobile communication system (5G) will begin in March 2020 in Japan, making it the next generation. The use of higher frequency bands is being considered in the 6th generation mobile communication system (6G).
In order to support such higher capacity and higher speeds, materials with low relative dielectric constant and low dielectric loss tangent are required for the parts of communication equipment and radar equipment used.

In Patent Document 1, the applicant provides a millimeter-wave radar cover in which a resin composition containing a thermoplastic resin and alumina (B) has a low dielectric constant and a low dielectric loss tangent, and has excellent millimeter-wave transparency. proposed to do so. However, alumina is a material with a high absolute value of dielectric constant, and Example 2 containing polycarbonate resin of Patent Document 1 shows that the dielectric constant is 3.7 and the dielectric loss tangent is 0.0093. There is.
In order to reduce the transmission loss of electromagnetic waves, the magnitude of the dielectric loss that occurs in a material is proportional to the product of the square root of the material's relative permittivity and the dielectric loss tangent, so it is necessary to use a material that has both a small relative permittivity and a small dielectric loss tangent. However, the above-mentioned dielectric constant and dielectric loss tangent are not sufficient for a material that can handle large capacity and high speed.

Furthermore, in Patent Document 2, the applicant discovered that a polycarbonate resin containing a specific bisphenol unit has a low dielectric loss tangent, and by blending this with a general-purpose polycarbonate resin, both the relative dielectric constant and the dielectric loss tangent were improved. We proposed a cover for millimeter-wave radar made of polycarbonate resin material with reduced energy consumption. Although this polycarbonate resin material is an effective material, there is a problem in that its use is limited due to its high price.

It is considered to include polystyrene as a resin with good dielectric properties, but polystyrene has disadvantages of poor compatibility with general-purpose polycarbonate resins, poor heat resistance, and poor impact resistance.

In addition, base materials and covers for antennas are required to have high rigidity and impact resistance in order to maintain sufficient rigidity and to withstand wind pressure when installed outdoors. However, it is required to have excellent heat resistance so that its functionality is not impaired.

Japanese Patent Application Publication No. 2013-102512 JP 2019-195137 Publication

The present invention was made in view of the above circumstances, and its object (problem) is to provide a polycarbonate resin composition that is low cost, has a low dielectric constant, a low dielectric loss tangent, and has excellent heat resistance, rigidity, and impact resistance. It's about providing things.
When a polystyrene resin is blended with a general-purpose polycarbonate resin, the dielectric loss tangent is low, but the impact resistance is greatly reduced. Therefore, when adding an elastomer, the impact resistance improves, but if too much is added, there is a problem that strength, rigidity, and heat resistance decrease.

In order to solve the above problems, the present inventors have made extensive studies and have found that the difference in melt viscosity between polycarbonate resin (A) and polystyrene resin (B) is reduced, and the melt viscosity ratio of both is kept within a specific range. The inventors have found that the compatibility between the two can be improved and the above-mentioned problems can be solved by doing so, and the present invention has been completed.
The present invention relates to the following polycarbonate resin composition.

1. Polycarbonate resin (A) containing 30 to 150 parts by mass of polystyrene resin (B) and 3 to 60 parts by mass of elastomer (C) with respect to 100 parts by mass of polycarbonate resin (A) at 260 ° C. and 1216 sec ^-1 . A polycarbonate resin composition characterized in that the polystyrene resin (B) has a melt viscosity ratio (ηA/ηB) in the range of 4.5 to 12.5.
2. The elastomer (C) is one or more selected from butadiene/methyl (meth)acrylate copolymer, butadiene/methyl (meth)acrylate/styrene copolymer, and styrene/ethylene/butylene/styrene copolymer. The polycarbonate resin composition according to 1 above.
3. 3. The polycarbonate resin composition according to 1 or 2 above, which has a dielectric loss tangent of 0.0040 or less at a frequency of 5.8 GHz.
4. 4. The polycarbonate resin composition according to any one of 1 to 3 above, wherein the content ratio [(B)/(C)] of the polystyrene resin (B) and the elastomer (C) in the polycarbonate resin composition is 9 or less.
5. Any of 1 to 4 above, which does not contain an acrylonitrile-butadiene-styrene copolymer content, or if it does, the content is 10 parts by mass or less per 100 parts by mass of the polycarbonate resin (A). The polycarbonate resin composition described.
6. A molded article of the polycarbonate resin composition according to any one of 1 to 5 above.

The polycarbonate resin composition of the present invention is low in cost, has excellent impact resistance, toughness, rigidity, and heat resistance, has low dielectric constant and dielectric loss tangent, and has small transmission attenuation of electromagnetic waves, so it can be used in 5G and 6G. It can be suitably used as electronic and electrical equipment parts that can handle high frequency bands such as, especially antenna base materials, antenna covers, etc., and can sufficiently ensure reliability of electromagnetic waves.

Hereinafter, the present invention will be described in detail by showing embodiments, examples, etc.
In addition, in this specification, unless otherwise specified, "~" is used to include the numerical values described before and after it as a lower limit value and an upper limit value.

The polycarbonate resin composition of the present invention contains 30 to 150 parts by mass of polystyrene resin (B) and 3 to 60 parts by mass of elastomer (C) based on 100 parts by mass of polycarbonate resin (A), and is heated at 260°C for 1216 sec. ^-1 is characterized in that the melt viscosity ratio (ηA/ηB) of the polycarbonate resin (A) and polystyrene resin (B) is in the range of 4.5 to 12.5.

Hereinafter, each component constituting the polycarbonate resin composition used in the polycarbonate resin composition of the present invention will be explained in detail.

[Polycarbonate resin (A)]
Although there are no specific restrictions on the specific type of polycarbonate resin, examples thereof include polycarbonate polymers obtained by reacting a dihydroxy compound and a carbonate precursor. At this time, in addition to the dihydroxy compound and the carbonate precursor, a polyhydroxy compound or the like may be reacted. Alternatively, a method in which carbon dioxide is used as a carbonate precursor and is reacted with a cyclic ether may also be used. Further, the polycarbonate polymer may be linear or branched. Furthermore, the polycarbonate polymer may be a monopolymer consisting of one type of repeating unit, or a copolymer having two or more types of repeating units. At this time, the copolymer can be selected from various copolymerization forms such as a random copolymer and a block copolymer. Note that such a polycarbonate polymer is usually a thermoplastic resin.

Further, polycarbonate resins can be classified into aromatic polycarbonate resins in which the carbons directly bonded to the carbonic acid bonds are aromatic carbons, and aliphatic polycarbonate resins in which the carbons directly bonded to carbonate bonds are aliphatic carbons, and either of them can be used. Among these, aromatic polycarbonate resins are preferred from the viewpoints of heat resistance, mechanical properties, electrical properties, and the like.

Among the monomers that are raw materials for aromatic polycarbonate resin, examples of aromatic dihydroxy compounds include:
Dihydroxybenzenes such as 1,2-dihydroxybenzene, 1,3-dihydroxybenzene (i.e. resorcinol), 1,4-dihydroxybenzene;
Dihydroxybiphenyls such as 2,5-dihydroxybiphenyl, 2,2'-dihydroxybiphenyl, 4,4'-dihydroxybiphenyl;
2,2'-dihydroxy-1,1'-binaphthyl, 1,2-dihydroxynaphthalene, 1,3-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, 1 , 7-dihydroxynaphthalene, 2,7-dihydroxynaphthalene and other dihydroxynaphthalenes;
2,2'-dihydroxydiphenyl ether, 3,3'-dihydroxydiphenyl ether, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxy-3,3'-dimethyldiphenyl ether, 1,4-bis(3-hydroxyphenoxy) Dihydroxydiarylethers such as benzene and 1,3-bis(4-hydroxyphenoxy)benzene;

2,2-bis(4-hydroxyphenyl)propane (i.e. bisphenol A),
1,1-bis(4-hydroxyphenyl)propane,
α,α'-bis(4-hydroxyphenyl)-1,4-diisopropylbenzene,
1,3-bis[2-(4-hydroxyphenyl)-2-propyl]benzene,
bis(4-hydroxyphenyl)methane,
bis(4-hydroxyphenyl)cyclohexylmethane,
bis(4-hydroxyphenyl)phenylmethane,
bis(4-hydroxyphenyl)(4-propenylphenyl)methane,
bis(4-hydroxyphenyl)diphenylmethane,
bis(4-hydroxyphenyl)naphthylmethane,
1,1-bis(4-hydroxyphenyl)ethane,
1,1-bis(4-hydroxyphenyl)-1-phenylethane (i.e. bisphenol AP),
1,1-bis(4-hydroxyphenyl)-1-naphthylethane,

1,1-bis(4-hydroxyphenyl)butane,
2,2-bis(4-hydroxyphenyl)butane,
2,2-bis(4-hydroxyphenyl)pentane,
1,1-bis(4-hydroxyphenyl)hexane,
2,2-bis(4-hydroxyphenyl)hexane,
1,1-bis(4-hydroxyphenyl)octane,
2,2-bis(4-hydroxyphenyl)octane,
4,4-bis(4-hydroxyphenyl)heptane,
2,2-bis(4-hydroxyphenyl)nonane,
1,1-bis(4-hydroxyphenyl)decane,
1,1-bis(4-hydroxyphenyl)dodecane,
Bis(hydroxyaryl) alkanes such as;

9,9-bis(4-hydroxyphenyl)fluorene,
Bisphenols containing cardo structure such as 9,9-bis(4-hydroxy-3-methylphenyl)fluorene;
4,4'-dihydroxydiphenyl sulfide,
Dihydroxydiaryl sulfides such as 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfide;
4,4'-dihydroxydiphenyl sulfoxide,
Dihydroxydiaryl sulfoxides such as 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfoxide;
4,4'-dihydroxydiphenyl sulfone,
Dihydroxydiarylsulfones such as 4,4'-dihydroxy-3,3'-dimethyldiphenylsulfone;
etc.

Among these, bis(hydroxyaryl)alkanes are preferred, and bis(4-hydroxyphenyl)alkanes are particularly preferred, and 2,2-bis(4-hydroxyphenyl)propane (i.e. Bisphenol A) is preferred.
In addition, one type of aromatic dihydroxy compound may be used, or two or more types may be used in combination in any combination and ratio.

Among the monomers that serve as raw materials for aromatic polycarbonate resins, carbonyl halides, carbonate esters, and the like are used as examples of carbonate precursors. In addition, one type of carbonate precursor may be used, or two or more types may be used in combination in any combination and ratio.

Specific examples of carbonyl halides include phosgene; haloformates such as bischloroformates of dihydroxy compounds and monochloroformates of dihydroxy compounds.

Specific examples of carbonate esters include diaryl carbonates such as diphenyl carbonate and ditolyl carbonate; dialkyl carbonates such as dimethyl carbonate and diethyl carbonate; biscarbonates of dihydroxy compounds, monocarbonates of dihydroxy compounds, and cyclic carbonates. Examples include carbonate forms of dihydroxy compounds such as .

The method for producing polycarbonate resin is not particularly limited, and any method can be employed. Examples include interfacial polymerization, melt transesterification, pyridine method, ring-opening polymerization of cyclic carbonate compounds, and solid phase transesterification of prepolymers.

The molecular weight of the polycarbonate resin is arbitrary and may be selected and determined as appropriate, but the viscosity average molecular weight Mv is usually 10,000 or more, preferably 14,000 or more, more preferably 16,000 or more, and usually 40,000 or less, preferably 30,000 or less. By setting the viscosity average molecular weight to the lower limit of the above range or more, the mechanical strength of the resin composition can be further improved. On the other hand, by controlling the viscosity average molecular weight to be less than or equal to the upper limit of the above range, it is possible to suppress and improve the decrease in fluidity of the resin composition, improve molding processability, and facilitate molding.
Note that two or more types of polycarbonate resins having different viscosity average molecular weights may be mixed and used, and in this case, polycarbonate resins having a viscosity average molecular weight outside the above-mentioned preferred range may be mixed.

The polycarbonate resin preferably contains a high molecular weight polycarbonate resin, for example, preferably a polycarbonate resin having a viscosity average molecular weight Mv of 50,000 to 95,000. The viscosity average molecular weight of the high molecular weight polycarbonate resin is more preferably 55,000 or more, still more preferably 60,000 or more, especially 61,000 or more, particularly preferably 62,000 or more, and more preferably 90,000 or less, even more preferably 85,000 or less, and especially It is preferably 80,000 or less, especially 75,000 or less, especially 70,000 or less.

When a high molecular weight polycarbonate resin is included, it is preferably included in the polycarbonate resin in an amount of 5% by mass or more, more preferably 10% by mass or more, and even more preferably 15% by mass or more. Note that the upper limit is preferably 40% by mass or less, more preferably 30% by mass or less.

In the present invention, the viscosity average molecular weight Mv of the polycarbonate resin is determined by using methylene chloride as a solvent, determining the intrinsic viscosity [η] (unit: dl/g) at a temperature of 25°C using an Ubbelohde viscometer, and using Schnell's method. The viscosity formula, i.e.
It means the value calculated from η=1.23×10 ⁻⁴ Mv ^0.83 .
Moreover, the intrinsic viscosity [η] is a value calculated by measuring the specific viscosity [η _sp ] at each solution concentration [C] (g/dl) and using the following formula.

The terminal hydroxyl group concentration of the polycarbonate resin is arbitrary and may be selected and determined as appropriate, but it is usually 2000 ppm or less, preferably 1500 ppm or less, more preferably 1000 ppm or less. Thereby, the retention heat stability and color tone of the resin composition of the present invention can be further improved. Moreover, the lower limit is usually 10 ppm or more, preferably 30 ppm or more, and more preferably 40 ppm or more, especially for polycarbonate resins manufactured by melt transesterification. Thereby, it is possible to suppress a decrease in molecular weight and further improve the mechanical properties of the resin composition of the present invention.

Note that the unit of the terminal hydroxyl group concentration is the mass of the terminal hydroxyl group expressed in ppm relative to the mass of the polycarbonate resin. The measurement method is colorimetric determination using titanium tetrachloride/acetic acid method (method described in Macromol. Chem. 88 215 (1965)).
Further, in order to improve the appearance and fluidity of the molded product, the polycarbonate resin may contain a polycarbonate oligomer. The viscosity average molecular weight Mv of this polycarbonate oligomer is usually 1,500 or more, preferably 2,000 or more, and usually 9,500 or less, preferably 9,000 or less. Furthermore, it is preferable that the contained polycarbonate oligomer be 30% by mass or less of the polycarbonate resin (including the polycarbonate oligomer).

Polycarbonate resin is manufactured not only from virgin resin, but also from polycarbonate resin recycled from used products (so-called material recycled polycarbonate resin), or from polycarbonate resin that has been chemically decomposed and returned to raw materials. It may be a polycarbonate resin (so-called chemically recycled polycarbonate resin), preferably containing both a virgin resin and a recycled resin, or a recycled polycarbonate resin. When containing recycled polycarbonate resin, the proportion of recycled polycarbonate resin in the polycarbonate resin is preferably 40% or more, 50% or more, 60% or more, or 80% or more, and it is also preferable that the recycled polycarbonate resin is 100%.

The polycarbonate resin (A) preferably has a melt viscosity (ηA) at 260°C and 1216 cm ^-1 in the range of 100 to 2000 Pa·s, and the viscosity difference between the polystyrene resin (B) and the polystyrene resin (B) is brought closer to each other. In order to set the melt viscosity ratio (ηA/ηB) to 4.5 to 12.5 and maintain toughness, it is more preferably 400 Pa·s or more, especially 500 Pa·s or more, especially 600 Pa·s or more. preferable. Moreover, it is more preferably 1,500 Pa·s or less, especially 1,250 Pa·s or less, particularly preferably 1,000 Pa·s or less.

[Polystyrene resin (B)]
The polycarbonate resin composition of the present invention contains 30 to 150 parts by mass of polystyrene resin (B) based on 100 parts by mass of polycarbonate resin (A).

The polystyrene resin is preferably a styrene homopolymer, or contains other aromatic vinyl monomers such as α-methylstyrene, paramethylstyrene, vinyltoluene, vinylxylene, etc. in an amount of less than 50% by mass. It may also be a copolymerized one.

Further, the polystyrene resin may be a rubber reinforced polystyrene resin. The rubber-reinforced polystyrene resin is preferably one copolymerized or blended with a butadiene rubber component, and the amount of the butadiene rubber component is usually 1% by mass or more and less than 50% by mass, preferably 3 to 40% by mass. , more preferably 5 to 30% by weight, still more preferably 5 to 20% by weight. High impact polystyrene (HIPS) is particularly preferred as the rubber reinforced polystyrene resin.
As the polystyrene resin, styrene homopolymer, high impact polystyrene, or a mixture thereof is particularly preferred.

The content of the polystyrene resin (B) is 30 to 150 parts by mass based on 100 parts by mass of the polycarbonate resin (A), preferably 40 parts by mass or more, more preferably 50 parts by mass or more, especially 60 parts by mass. parts or more, especially 70 parts by weight or more, preferably 120 parts by weight or less, more preferably 110 parts by weight or less, more preferably 100 parts by weight or less, especially 95 parts by weight or less, especially 90 parts by weight or less.

However, since copolymers containing acrylonitrile such as acrylonitrile-butadiene-styrene copolymers (ABS resins) tend to increase the dielectric loss tangent, it is preferable not to contain them. A) It is preferably 10 parts by mass or less, more preferably 7 parts by mass or less, and particularly preferably 5 parts by mass or less, 3 parts by mass or less, 2 parts by mass or less, and 1 part by mass or less.

The melt viscosity (ηB) of the polystyrene resin (B) at 260° C. and 1216 cm ⁻¹ is preferably in the range of 30 to 300 Pa·s, more preferably 40 Pa·s or more, especially 50 Pa·s or more, especially 60 Pa. - It is preferable that it is s or more. Moreover, it is more preferably 250 Pa·s or less, especially 200 Pa·s or less, particularly preferably 150 Pa·s or less.

In the present invention, the melt viscosity ratio (ηA/ηB) between the melt viscosity ηA of the polycarbonate resin (A) and the melt viscosity ηB of the polystyrene resin (B) at 260°C and 1216 sec ^-1 is 4.5 to 12. It is in the range of 5. By reducing the difference in melt viscosity between polycarbonate resin (A) and polystyrene resin (B) and setting the melt viscosity ratio within this range, the compatibility between the two is improved and impact resistance is improved. I can do it.
ηA/ηB is preferably 6.0 or more, more preferably 7.0 or more, especially 8.0 or more, particularly preferably 9.0 or more, preferably 12.0 or less, more preferably 11. It is preferably 5 or less, especially 11.0 or less, particularly 10.5 or less.

Note that the melt viscosity of the polycarbonate resin (A) and the polystyrene resin (B) at 260° C. and 1216 sec ⁻¹ is a value measured using a capillary rheometer in accordance with ISO 11443. Specifically, using an orifice with a capillary diameter of 1 mm and a capillary length of 10 mm, the melting was caused by the stress caused when a piston was pushed into a furnace body with an inner diameter of 9.55 mm heated to 260°C at a piston speed of 100 mm/min. Viscosity can be calculated.

[Elastomer (C)]
The elastomer is preferably a copolymer obtained by graft copolymerizing a rubber component with a monomer component copolymerizable with the rubber component. The method for producing such a graft copolymer may be any production method such as bulk polymerization, solution polymerization, suspension polymerization, or emulsion polymerization, and the method of copolymerization may be single-stage grafting or multi-stage grafting. Good too.

The above-mentioned rubber component usually has a glass transition temperature of 0°C or lower, preferably -20°C or lower, and more preferably -30°C or lower. Specific examples of rubber components include polybutadiene rubber, polyisoprene rubber or hydrogenated products thereof, butadiene-acrylic composite rubber, styrene-butadiene rubber, ethylene-α olefin rubber such as ethylene-propylene rubber, ethylene-butene rubber, and ethylene-octene rubber. Examples include rubber, ethylene-acrylic rubber, and the like. These may be used alone or in combination of two or more. Among these, polybutadiene rubber, hydrogenated polyisoprene rubber, and styrene-butadiene rubber are preferred.
If the rubber component is polyalkyl acrylate rubber such as polybutyl acrylate, poly(2-ethylhexyl acrylate), butyl acrylate/2-ethylhexyl acrylate copolymer, or silicone rubber such as organopolysiloxane rubber, the dielectric loss tangent is This is not desirable as it tends to rise.

Specific examples of monomer components that can be graft copolymerized with the rubber component include aromatic vinyl compounds, vinyl cyanide compounds, (meth)acrylic acid ester compounds, (meth)acrylic acid compounds, glycidyl (meth)acrylate, etc. Epoxy group-containing (meth)acrylic acid ester compounds; maleimide compounds such as maleimide, N-methylmaleimide, and N-phenylmaleimide; α,β-unsaturated carboxylic acid compounds such as maleic acid, phthalic acid, and itaconic acid, and their anhydrides (eg, maleic anhydride, etc.). These monomer components may be used alone or in combination of two or more. Among these, aromatic vinyl compounds and (meth)acrylic acid ester compounds are preferred, and styrene, methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, cyclohexyl (meth)acrylate, ( Preferred examples include octyl meth)acrylate.

The elastomer is preferably of the core/shell type graft copolymer type. Among them, at least one rubber component selected from polybutadiene-containing rubber, ethylene/butylene rubber, and polybutyl acrylate-containing rubber is used as a core layer, and a shell layer formed by copolymerizing (meth)acrylic acid ester around the core layer. A core/shell type graft copolymer is preferred, and a core/shell type elastomer having a core of butadiene rubber is particularly preferred. In the above-mentioned core/shell type graft copolymer, one containing a rubber component in an amount of 40% by mass or more is preferable, and one containing a rubber component in an amount of 60% by weight or more is more preferable. Further, it is preferable that the (meth)acrylic acid component is contained in an amount of 10% by mass or more.

Preferred specific examples of these core/shell type graft copolymers include butadiene/methyl (meth)acrylate copolymer (MB), butadiene/methyl (meth)acrylate/styrene copolymer (MBS), and styrene/ethylene copolymer. /butylene/styrene copolymer (SEBS), etc. are preferably mentioned, butadiene/methyl (meth)acrylate copolymer (MB), butadiene/methyl (meth)acrylate/styrene copolymer (MBS), and styrene/ethylene /butylene/styrene copolymer (SEBS) is more preferred.

The content of the elastomer (C) is 3 to 60 parts by mass based on 100 parts by mass of the polycarbonate resin (A). By containing it in such an amount, the impact resistance, rigidity, and heat resistance of the polycarbonate resin composition, as well as the dielectric constant and dielectric loss tangent can be made to be well-balanced. The content of the elastomer (C) is preferably 5 parts by mass or more, more preferably 7.5 parts by mass or more, especially 10 parts by mass or more, particularly preferably 15 parts by mass or more, and 55 parts by mass or less, more preferably 50 parts by mass. parts by weight or less, particularly preferably 45 parts by weight or less, 40 parts by weight or less, 35 parts by weight or less, 30 parts by weight or less, particularly 25 parts by weight or less.
In addition, if the content ratio of polystyrene resin (B) and elastomer (C) in the polycarbonate resin composition is 9 or less (content of polystyrene resin (B)/content of elastomer (C)), notched This is preferred because the Charpy impact strength value is high.

[Stabilizer]
The polycarbonate resin composition of the present invention preferably contains a stabilizer, and the stabilizer is preferably a phosphorus stabilizer (thermal stabilizer) or a phenol stabilizer (antioxidant).

Any known phosphorus stabilizer can be used. Specific examples include oxoacids of phosphorus such as phosphoric acid, phosphonic acid, phosphorous acid, phosphinic acid, and polyphosphoric acid; metal salts of acidic pyrophosphate such as sodium acidic pyrophosphate, potassium acidic pyrophosphate, and calcium acidic pyrophosphate; phosphoric acid; Phosphates of Group 1 or Group 2B metals such as potassium, sodium phosphate, cesium phosphate, and zinc phosphate; examples include organic phosphate compounds, organic phosphite compounds, and organic phosphonite compounds; Particularly preferred.

Examples of organic phosphite compounds include triphenyl phosphite, tris (monononylphenyl) phosphite, tris (monononyl/dinonyl phenyl) phosphite, tris (2,4-di-tert-butylphenyl) phosphite, monooctyl Diphenyl phosphite, dioctyl monophenyl phosphite, monodecyl diphenyl phosphite, didecyl monophenyl phosphite, tridecyl phosphite, trilauryl phosphite, tristearyl phosphite, 2,2-methylenebis(4,6-di- Examples include tert-butylphenyl) octyl phosphite.
Specific examples of such organic phosphite compounds include, for example, "ADEKA STAB 1178", "ADEKA STAB 2112", "ADEKA STAB HP-10" manufactured by ADEKA, "JP-351" manufactured by Johoku Kagaku Kogyo Co., Ltd. JP-360'', ``JP-3CP'', BASF's ``Irgafoss 168'', etc.
In addition, one type of phosphorus stabilizer may be contained, or two or more types may be contained in any combination and ratio.

The content of the phosphorus stabilizer is preferably 0.01 parts by mass or more, more preferably 0.03 parts by mass or more, and usually 1 part by mass or less, preferably is 0.7 parts by mass or less, more preferably 0.5 parts by mass or less. If the content of the phosphorus stabilizer is less than the lower limit of the above range, the thermal stabilizing effect may be insufficient, and if the content of the phosphorus stabilizer exceeds the upper limit of the above range, the effect may be insufficient. may reach a peak and become uneconomical.

Examples of phenolic stabilizers include hindered phenolic antioxidants. Specific examples include pentaerythritol tetrakis [3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl) ) propionate, thiodiethylenebis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], N,N'-hexane-1,6-diylbis[3-(3,5-di- tert-butyl-4-hydroxyphenyl)propionamide], 2,4-dimethyl-6-(1-methylpentadecyl)phenol, diethyl[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl ]Methyl]phosphoate, 3,3',3",5,5',5"-hexa-tert-butyl-a,a',a"-(mesitylene-2,4,6-tolyl)tri-p- Cresol, 4,6-bis(octylthiomethyl)-o-cresol, ethylenebis(oxyethylene)bis[3-(5-tert-butyl-4-hydroxy-m-tolyl)propionate], hexamethylenebis[3 -(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-1,3,5- Triazine-2,4,6(1H,3H,5H)-trione,2,6-di-tert-butyl-4-(4,6-bis(octylthio)-1,3,5-triazin-2-ylamino ) phenol, 2-[1-(2-hydroxy-3,5-di-tert-pentylphenyl)ethyl]-4,6-di-tert-pentylphenyl acrylate, and the like.

Among them, pentaerythritol tetrakis [3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate are preferred. . Specific examples of such phenolic antioxidants include "Irganox 1010" and "Irganox 1076" manufactured by BASF, "ADEKA STAB AO-50" and "ADEKA STAB AO-60" manufactured by ADEKA, etc. can be mentioned.
In addition, one type of phenolic stabilizer may be contained, or two or more types may be contained in any combination and ratio.

The content of the phenolic stabilizer is preferably 0.01 parts by mass or more, and usually 1 part by mass or less, preferably 0.5 parts by mass or less, based on 100 parts by mass of the polycarbonate resin (A). By setting the content of the phenol stabilizer to the lower limit of the above range or more, the effect as a phenol stabilizer can be sufficiently obtained. Furthermore, by keeping the content of the phenolic stabilizer below the upper limit of the above range, the effect does not reach a plateau and is economical.

[Release agent]
It is preferable that the polycarbonate resin composition of the present invention contains a mold release agent. Examples of the mold release agent include aliphatic carboxylic acids, esters of aliphatic carboxylic acids and alcohols, aliphatic hydrocarbon compounds having a number average molecular weight of 200 to 15,000, and polysiloxane silicone oils.

As aliphatic carboxylic acids, mention may be made, for example, of saturated or unsaturated aliphatic mono-, di- or trivalent carboxylic acids. Here, aliphatic carboxylic acid also includes alicyclic carboxylic acid. Among these, preferred aliphatic carboxylic acids are monovalent or divalent carboxylic acids having 6 to 36 carbon atoms, and aliphatic saturated monovalent carboxylic acids having 6 to 36 carbon atoms are more preferred. Specific examples of such aliphatic carboxylic acids include palmitic acid, stearic acid, caproic acid, capric acid, lauric acid, arachidic acid, behenic acid, lignoceric acid, cerotic acid, melisic acid, tetraliacontanoic acid, montanic acid, and adipine. Examples include acids, azelaic acid, and the like.

As the aliphatic carboxylic acid in the ester of aliphatic carboxylic acid and alcohol, for example, the same aliphatic carboxylic acids as mentioned above can be used. On the other hand, examples of the alcohol include saturated or unsaturated monohydric or polyhydric alcohols. These alcohols may have a substituent such as a fluorine atom or an aryl group. Among these, monohydric or polyhydric saturated alcohols having 30 or less carbon atoms are preferred, and aliphatic saturated monohydric alcohols or aliphatic saturated polyhydric alcohols having 30 or less carbon atoms are more preferred. Note that the term aliphatic herein is used to include alicyclic compounds as well.

Specific examples of such alcohols include octanol, decanol, dodecanol, stearyl alcohol, behenyl alcohol, ethylene glycol, diethylene glycol, glycerin, pentaerythritol, 2,2-dihydroxyperfluoropropanol, neopentylene glycol, ditrimethylolpropane, dipentaerythritol, and the like. can be mentioned.

Note that the above ester may contain an aliphatic carboxylic acid and/or an alcohol as an impurity. Moreover, the above-mentioned ester may be a pure substance, but may also be a mixture of a plurality of compounds. Furthermore, the aliphatic carboxylic acid and alcohol that combine to form one ester may be used alone or in combination of two or more in any combination and ratio.

Specific examples of esters of aliphatic carboxylic acids and alcohols include beeswax (a mixture containing myricyl palmitate as the main component), stearyl stearate, behenyl behenate, stearyl behenate, glycerin monopalmitate, and glycerin monostearate. ester, glycerin distearate, glycerin tristearate, pentaerythritol monopalmitate, pentaerythritol monostearate, pentaerythritol distearate, pentaerythritol tristearate, pentaerythritol tetrastearate, and the like.

Examples of the aliphatic hydrocarbons having a number average molecular weight of 200 to 15,000 include liquid paraffin, paraffin wax, microwax, polyethylene wax, Fischer-Tropsch wax, and α-olefin oligomers having 3 to 12 carbon atoms. Note that the aliphatic hydrocarbons herein also include alicyclic hydrocarbons. Moreover, these hydrocarbons may be partially oxidized.
Among these, paraffin wax, polyethylene wax, or a partial oxide of polyethylene wax is preferred, and paraffin wax and polyethylene wax are more preferred.
Further, the number average molecular weight of the aliphatic hydrocarbon is preferably 5,000 or less.
The aliphatic hydrocarbon may be a single substance, or a mixture of various components and molecular weights can be used as long as the main component is within the above range.

Examples of the polysiloxane silicone oil include dimethyl silicone oil, methylphenyl silicone oil, diphenyl silicone oil, and fluorinated alkyl silicone.

In addition, the above-mentioned mold release agents may be contained alone or in any combination and ratio of two or more types.

The content of the mold release agent is usually 0.001 parts by mass or more, preferably 0.01 parts by mass or more, and usually 2 parts by mass or less, preferably 1 part by mass, based on 100 parts by mass of the polycarbonate resin (A). Parts by mass or less. If the content of the mold release agent is less than the lower limit of the above range, the mold release effect may not be sufficient, and if the content of the mold release agent exceeds the upper limit of the range, the hydrolysis resistance may be insufficient. This may lead to a decrease in performance and contamination of the mold during injection molding.

[Additives, etc.]
The polycarbonate resin composition may contain other additives other than those mentioned above, such as ultraviolet absorbers, fillers, reinforcing materials (carbon fibers, glass fibers), pigments, dyes, flame retardants, antistatic agents, plasticizers, and compatibilizers. It may contain additives such as additives, and resins other than the polycarbonate resin (A) and polystyrene resin (B). These additives or other resins may be used alone or in combination of two or more.
In addition, when containing other resins than the above-mentioned polycarbonate resin (A) and polystyrene resin (B), the content is preferably 40 parts by mass or less with respect to 100 parts by mass of polycarbonate resin (A). , more preferably 30 parts by mass or less, further preferably 20 parts by mass or less, 10 parts by mass or less, particularly preferably 5 parts by mass or less.

[Method for producing polycarbonate resin composition]
There are no restrictions on the method for producing the polycarbonate resin composition, and a wide range of known methods for producing polycarbonate resin compositions can be adopted, and each essential component and other components blended as necessary can be prepared using a tumbler, a Henschel mixer, etc. Examples include a method of pre-mixing using various mixers, and then melt-kneading with a mixer such as a Banbury mixer, a roll, a Brabender, a single-screw kneading extruder, a twin-screw kneading extruder, or a kneader. Note that the melt-kneading temperature is not particularly limited, but is usually in the range of 240 to 320°C.

Pellets obtained by pelletizing the above-mentioned polycarbonate resin composition can be molded by various molding methods to produce molded products. Alternatively, the resin melt-kneaded in an extruder can be directly molded into a molded product without going through pellets.
As a method for manufacturing the molded article, any molding method generally employed for polycarbonate resin compositions can be adopted. Examples include injection molding, ultra-high-speed injection molding, injection compression molding, two-color molding, gas-assisted blow molding, molding using an insulated mold, and rapid heating mold. Molding method, foam molding (including supercritical fluid), insert molding, IMC (in-mold coating molding) molding method, extrusion molding method, sheet molding method, thermoforming method, rotational molding method, lamination molding method, press molding method, Examples include blow molding, and a molding method using a hot runner method can also be used.
Among these, injection molding methods such as injection molding method, ultra-high speed injection molding method, and injection compression molding method are preferred.

Furthermore, a hard coat layer may be provided on the surface of the molded product. As the hard coat agent for forming the hard coat layer, known materials can be used as appropriate. For example, various hard coat agents such as silicone-based, acrylic-based, silazane-based, and urethane-based hard coat agents can be used. can. In order to improve adhesion and weather resistance, a two-coat type hard coat agent may be used in which a primer layer is provided before applying the hard coat agent. There are no particular limitations on the coating method of the hard coating agent, but any of spray coating, dip coating, flow coating, spin coating, bar coating, curtain coating, die coating, gravure coating, roll coating, blade coating, air knife coating, etc. It can also be applied by the following coating method.
The thickness of the hard coat layer is preferably 1 to 50 μm, more preferably 5 to 30 μm.

The polycarbonate resin composition of the present invention has a small dielectric loss tangent, and the dielectric loss tangent at a frequency of 5.8 GHz is preferably 0.0040 or less, more preferably 0.0038 or less, still more preferably 0.0036 or less, and particularly preferably is 0.0034 or less.
Further, the dielectric constant of the polycarbonate resin composition of the present invention is also small, preferably 2.8 or less, more preferably 2.7 or less, still more preferably 2.6 or less.
Specific methods for measuring dielectric loss tangent and dielectric constant are as described in Examples.

Furthermore, the polycarbonate resin composition of the present invention has excellent heat resistance, and its deflection temperature under load, which is an indicator thereof, is preferably higher than 86°C, more preferably higher than 90°C, and even more preferably 92°C or higher. . The deflection temperature under load was measured in accordance with ISO75-2, and the specific method is as described in the Examples.
Further, the polycarbonate resin composition of the present invention has excellent impact resistance, and preferably has a Charpy impact strength of NB (non-break) without a notch and 10 kJ/m ² or more with a notch. Charpy impact strength was measured in accordance with ISO179-1, 2, and the specific method is as described in the Examples.
Further, the polycarbonate resin composition of the present invention preferably has excellent rigidity, and has a bending modulus of 2000 MPa or more and a bending strength of 67 MPa or more. The bending elastic modulus and bending strength were measured in accordance with ISO178, and the specific method is as described in Examples.
Further, the polycarbonate resin composition of the present invention preferably has excellent toughness and a nominal tensile strain at break of 20% or more. The measurement of the nominal tensile strain at failure was carried out in accordance with ISO527, and the specific method thereof is as described in the Examples.

The polycarbonate resin composition of the present invention is preferably used particularly in electronic and electrical equipment parts that use electromagnetic waves with a frequency of 1 GHz or higher. Electronic and electrical equipment parts made of the polycarbonate resin composition of the present invention can be used in a wide frequency band of 1 GHz or more. It can also be applied to the frequency band up to 52.6GHz of the 5G wireless communication standard "NR", up to about 90GHz which is being considered for use in future 5G evolution, and sub-terahertz waves such as 90G to 300GHz for 6G. It is. Of course, it is also suitable for existing low frequency bands and bands such as 10 to 20 GHz of 6G low band/mid band.

Electronic and electrical equipment parts for which molded products of the polycarbonate resin composition of the present invention can be used include housings of electronic and electrical equipment, circuit boards, semiconductor interlayer insulation films, antenna parts (substrates, antenna covers, radar covers), and high-frequency coaxial Cable insulation materials Base parts such as resistors, switches, capacitors, and photosensors, IC sockets and connectors, transportation equipment such as automobiles, bicycles, motorcycles, trucks, railway vehicles, helicopters, and aircraft, bulldozers, hydraulic excavators, cranes, etc. Construction machinery, commercial ships, special-purpose ships, fishing boats, ships such as ships, agricultural machinery such as tractors, harvesters, smartphones, tablets, wearable devices, computers, television receivers, VR goggles, cameras, speakers, drones, robots, Examples include parts for sensors, medical equipment, analytical equipment, etc., and are particularly suitable as antenna substrates, antenna covers, and radar covers.
Antenna covers and radar covers are housings, antenna covers (radomes), etc. that house or protect antenna modules that transmit or receive electromagnetic waves, as well as members installed on the path of electromagnetic waves transmitted and received from radar modules. including.

EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to Examples. However, the present invention is not interpreted as being limited to the following examples.
The raw materials used in the following Examples and Comparative Examples are shown in Table 1 below.

(Examples 1 to 19, Comparative Examples 1 to 4)
[Manufacture of polycarbonate resin composition pellets]
The components listed in Table 1 above were blended in the proportions (parts by mass) listed in Table 2-4 below, mixed in a tumbler for 20 minutes, and then mixed using a twin screw extruder (manufactured by Toshiba Machine Co., Ltd., TEM26SX). The mixture was melt-kneaded at a cylinder temperature of 260° C., and pellets of the polycarbonate resin composition were obtained by strand cutting.

<Relative permittivity, dielectric loss tangent>
After drying the pellets obtained by the above method at 100 ° C. for 5 hours, a molded product with a size of 100 mm x 150 mm x approximately 2 mm in thickness was obtained using an injection molding machine (ROBOSHOT S-2000i 150B, manufactured by Fanuc Corporation). . After cutting a 100 mm x 1 mm x 2 mm flat test piece from the flat test piece obtained by the above method, perturbation was performed using a network analyzer manufactured by KEYSIGHT and a cavity resonator manufactured by Kanto Denshi Application Development Co., Ltd. The relative dielectric constant and dielectric loss tangent at a frequency of 5.8 GHz were measured using the method.

<Bending modulus, bending strength>
After drying the pellets obtained by the above method at 100°C for 5 hours, they were molded using a NEX80III injection molding machine manufactured by Nissei Jushi Kogyo Co., Ltd. under the conditions of a cylinder temperature of 260°C, a mold temperature of 80°C, and a molding cycle of 50 seconds. Injection molding was performed to form an ISO multipurpose test piece (4 mm thick). Using the obtained test piece, a bending test was conducted at room temperature (23° C.) based on the ISO-178 standard, and the bending elastic modulus (unit: MPa) and bending strength (unit: MPa) were measured.

<Charpy impact strength>
After drying the pellets obtained by the above method at 100°C for 5 hours, they were molded using a NEX80III injection molding machine manufactured by Nissei Jushi Kogyo Co., Ltd. under the conditions of a cylinder temperature of 260°C, a mold temperature of 80°C, and a molding cycle of 50 seconds. Injection molding was performed to produce impact resistance test pieces with a thickness of 3 mm based on ISO 179-1 and 2. Using the obtained test pieces, the unnotched and notched Charpy impact strengths (unit: kJ/m ² ) were measured in a temperature environment of 23°C.

<Load deflection temperature>
After drying the pellets obtained by the above method at 100°C for 5 hours, they were molded using a NEX80III injection molding machine manufactured by Nissei Jushi Kogyo Co., Ltd. under the conditions of a cylinder temperature of 260°C, a mold temperature of 80°C, and a molding cycle of 50 seconds. Injection molding was performed to form an ISO multipurpose test piece (4 mm thick). Using the obtained test piece, the load deflection temperature (unit: °C) was measured under high load (1.80 MPa) conditions in accordance with ISO75-2 using a 6A-2 HDT measurement device manufactured by Toyo Seiki Co., Ltd. did.

<Tensile failure nominal strain (unit: %)>
After drying the pellets obtained by the above method at 100°C for 5 hours, they were molded using a NEX80III injection molding machine manufactured by Nissei Jushi Kogyo Co., Ltd. under the conditions of a cylinder temperature of 260°C, a mold temperature of 80°C, and a molding cycle of 50 seconds. Injection molding was performed to form an ISO multipurpose test piece (4 mm thick).
Using the obtained test piece, the nominal tensile strain at break (unit: %) was measured in accordance with the ISO527 standard.
The above evaluation results are shown in Tables 2 to 4 below. In addition, in the table, actual n represents Example n, and ratio n represents Comparative Example n.

As is clear from the above results, the polycarbonate resin composition of the present invention has excellent mechanical properties (impact resistance, toughness, rigidity, heat resistance, etc.) and excellent electrical properties (relative dielectric constant, dielectric loss tangent). On the other hand, in the case of the comparative example, results that achieved both mechanical properties and electrical properties could not be obtained.

The polycarbonate resin composition of the present invention has low dielectric constant and dielectric loss tangent, low transmission attenuation, and excellent heat resistance, impact resistance, and rigidity, so it is widely used in various electronic and electrical equipment parts that use electromagnetic waves. It can be used suitably.

Claims (6)

Polycarbonate resin (A) containing 30 to 150 parts by mass of polystyrene resin (B) and 3 to 60 parts by mass of elastomer (C) with respect to 100 parts by mass of polycarbonate resin (A) at 260 ° C. and 1216 sec ^-1 . A polycarbonate resin composition characterized in that the polystyrene resin (B) has a melt viscosity ratio (ηA/ηB) in the range of 4.5 to 12.5. The elastomer (C) is one or more selected from butadiene/methyl (meth)acrylate copolymer, butadiene/methyl (meth)acrylate/styrene copolymer, and styrene/ethylene/butylene/styrene copolymer. The polycarbonate resin composition according to claim 1. The polycarbonate resin composition according to claim 1 or 2, which has a dielectric loss tangent of 0.0040 or less at a frequency of 5.8 GHz. The polycarbonate resin composition according to claim 1 or 2, wherein the ratio [(B)/(C)] of the content of the polystyrene resin (B) and the elastomer (C) in the polycarbonate resin composition is 9 or less. The method according to claim 1 or 2, which does not contain the acrylonitrile-butadiene-styrene copolymer, or if it does, the content is 10 parts by mass or less based on 100 parts by mass of the polycarbonate resin (A). Polycarbonate resin composition. A molded article of the polycarbonate resin composition according to claim 1 or 2.