Thermoplastic resin composition and film

Abstract

To provide a thermoplastic resin composition which has high heat resistance and excellent low dielectric characteristics while improving compatibility between a polyester resin and a polycarbonate resin.SOLUTION: A thermoplastic resin composition contains a polycarbonate resin (A) including a repeating unit (a) represented by the following general formula (1), and a repeating unit (b) represented by the following general formula (2), and a polyester resin (B) containing 50 mol% or more of a 1,4-cyclohexanedimethanol unit as a diol component. In the formula (1) and formula (2), X and Y are each independently at least one selected from a single bond, an oxygen atom, a sulfur atom, and a divalent organic group (excluding unsubstituted group). Rx and Ry are each independently an alkyl group having 1 to 6 carbon atoms.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a thermoplastic resin composition and a film made of the thermoplastic resin composition. [Background technology]

[0002] In recent years, the increasing performance and functionality of electrical and electronic devices has created a need for high-speed information communication. For example, with the launch of 5G (fifth generation mobile communication system) high-speed communication services for smartphones, high-speed communication services are becoming widespread not only in the consumer sector but also in the industrial sector (factories, automobiles, and other vehicles). 5G's high-speed, large-capacity data communications use radio waves in the "millimeter wave" band (wavelength 1-10 mm, frequency 30-300 GHz). Advantages of millimeter waves include the large amount of data that can be transmitted at one time and the high-resolution images that can be obtained.

[0003] On the other hand, when a high-frequency digital signal such as the millimeter wave is transmitted through a circuit board, a dielectric loss occurs in which part of the transmitted digital signal is consumed as heat on the wiring of the circuit board, and the attenuated digital signal arrives at the receiving end, resulting in so-called "transmission loss." Therefore, measures to reduce transmission loss are also required for the components used. The transmission loss is the sum of dielectric loss and conductor loss, and materials with low dielectric loss are in demand.

[0004] Polyester films are a versatile resin film that has excellent heat resistance, weather resistance, mechanical strength, transparency, and other properties, and is readily available at a reasonable price, making them suitable for a variety of applications, including packaging materials and optical applications. However, their low dielectric properties have not been extensively studied. For example, Patent Document 1 discloses a laminated biaxially oriented polyester film containing 5 to 45% by volume of voids inside as a polyester film with excellent low dielectric properties. The inclusion of voids allows voids (air) to be dispersed, thereby achieving a low dielectric constant and a low dielectric loss tangent. However, since the void-containing laminated biaxially stretched polyester film described in Patent Document 1 is formed by mixing different materials to form the voids, it is difficult to control the size of the voids or the dispersion state of the different materials. For example, if the dispersion state of the different materials is insufficient, the desired low dielectric properties may not be obtained. Furthermore, depending on the different materials used, the inherent transparency of polyester film may not be achieved, and in addition, light may be refracted at the cavity interface, reducing transparency.

[0005] Polycarbonate resins are excellent in mechanical strength, electrical properties, transparency, etc., and are widely used as engineering plastics in various fields such as electrical and electronic equipment and automobiles. Patent Document 2 proposes a cover for millimeter-wave radar that uses a polycarbonate resin made from a bisphenol having a specific substituent group, thereby reducing the dielectric tangent and improving millimeter-wave transparency in the 75 GHz to 81 GHz range. Patent Document 3 proposes a thermoplastic resin composition containing a polycarbonate resin having two specific types of repeating units, which has excellent radio wave transmittance in the microwave and / or millimeter wave bands as well as excellent heat resistance and flame retardancy, a molded article thereof, and a housing for a communication device having a built-in microwave and / or millimeter wave antenna. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-352470 [Patent Document 2] Japanese Patent Application Publication No. 2019-197048 [Patent Document 3] International Publication No. 2021 / 039970 Summary of the Invention [Problem to be solved by the invention]

[0007] As mentioned above, polyester films are excellent in processability, weather resistance, mechanical strength, transparency, etc., but are not sufficient in terms of low dielectric properties. On the other hand, polycarbonate resins are excellent in heat resistance, mechanical strength, electrical properties, and transparency, as mentioned above, and the polycarbonate resins disclosed in Patent Documents 2 and 3 in particular have low dielectric properties. Therefore, it is expected that the use of a polycarbonate resin in combination with a polyester resin will make it possible to impart low dielectric properties while taking advantage of the properties of the polyester resin. Furthermore, since the production of circuit boards involves processes such as resist drying and solder reflow, materials used in such fields are required to have appropriate heat resistance. However, although the polycarbonate resins disclosed in Patent Documents 2 and 3 have low dielectric properties, they generally have poor compatibility with polyester resins and low heat resistance, making it difficult to use them in combination. Therefore, an object of the present invention is to provide a thermoplastic resin composition that has high heat resistance and excellent low dielectric properties while maintaining good compatibility between polyester resin and polycarbonate resin, and a film made of the thermoplastic resin composition. [Means for solving the problem]

[0008] The present inventors have found that by adjusting the copolymerization components of a polyester resin and a polycarbonate resin, the compatibility between the two can be improved, thereby solving the above-mentioned problems. The present invention was completed based on this finding, and the gist of the present invention has the following aspects. Note that the present invention is not limited to the following aspects, and also includes the scope of substitutions, modifications, etc. that may be made by those skilled in the art. [1] A thermoplastic resin composition comprising a polycarbonate resin (A) containing a repeating unit (a) represented by the following general formula (1) and a repeating unit (b) represented by the following general formula (2), and a polyester resin (B) containing 50 mol % or more of 1,4-cyclohexanedimethanol units as a diol component:

[0009] [ka]

[0010] [ka]

[0011] [In formula (1), X is at least one selected from a single bond, an oxygen atom, a sulfur atom, and a divalent organic group (excluding unsubstituted groups). Rx and Ry each independently represent an alkyl group having 1 to 6 carbon atoms. In formula (2), Y is at least one selected from a single bond, an oxygen atom, a sulfur atom, and a divalent organic group (excluding unsubstituted groups).]

[0012] [2] The thermoplastic resin composition according to [1], wherein in the formula (1), X is a divalent organic group represented by the following formula (3):

[0013] [ka]

[0014] [In formula (3), R1 and R2 each independently represent a hydrogen atom, a monovalent hydrocarbon group having 1 to 24 carbon atoms, or an alkoxy group having 1 to 24 carbon atoms. R1 and R2 may be bonded to each other to form a ring. * represents a bond to the benzene ring in formula (1)]

[0015] [3] The thermoplastic resin composition according to the above [2], wherein in the formula (3), R1 and R2 are both methyl groups.

[0016] [4] The thermoplastic resin composition according to any one of the above [1] to [3], wherein both Rx and Ry are methyl groups. [5] The thermoplastic resin composition according to any one of the above [1] to [4], wherein in the general formula (2), Y is a divalent organic group represented by the following formula (4):

[0017] [ka]

[0018] [In formula (4), R3 and R4 each independently represent a hydrogen atom, a monovalent hydrocarbon group having 1 to 24 carbon atoms, or an alkoxy group having 1 to 24 carbon atoms. R3 and R4 may be bonded to each other to form a ring. * represents a bond to the benzene ring in formula (2).]

[0019] [6] The thermoplastic resin composition according to any one of the above [1] to [5], wherein the formula (2) is represented by the following formula (5):

[0020] [ka]

[0021] [7] The thermoplastic resin composition according to any one of the above [1] to [6], further comprising an alicyclic diol other than 1,4-cyclohexanedimethanol as a diol component of the polyester resin (B). [8] The thermoplastic resin composition according to any one of the above [1] to [7], wherein the molar ratio of the repeating units (a) and (b) in the polycarbonate resin (A) is 95:5 to 40:60. [9] The thermoplastic resin composition according to any one of the above [1] to [8], wherein the polyester resin (B) contains 50 mol % or more of terephthalic acid units as the dicarboxylic acid component.

[10] The thermoplastic resin composition according to any one of the above [1] to [9], wherein the content of the polycarbonate resin (A) is 10 to 80 mass % and the content of the polyester resin (B) is 20 to 90 mass % in the total amount of the resin components.

[11] The thermoplastic resin composition according to any one of the above [1] to

[10] , which has a single glass transition temperature measured in accordance with JIS K7244 (1999).

[12] The thermoplastic resin composition according to any one of the above [1] to

[11] , which has a glass transition temperature of 110°C or higher as measured in accordance with JIS K7244 (1999).

[13] A film made of the thermoplastic resin composition according to any one of the above [1] to

[12] . [Effects of the Invention]

[0022] According to the present invention, it is possible to provide a thermoplastic resin composition that can improve the compatibility between a polyester resin and a polycarbonate resin, has high heat resistance, and has excellent low dielectric properties, and a film made of the thermoplastic resin composition. DETAILED DESCRIPTION OF THE INVENTION

[0023] [Thermoplastic resin composition] The thermoplastic resin composition of the present invention contains a polycarbonate resin (A) containing a repeating unit (a) represented by the following general formula (1) and a repeating unit (b) represented by the following general formula (2), and a polyester resin (B) containing 50 mol % or more of 1,4-cyclohexanedimethanol units as a diol component.

[0024] <Polycarbonate resin (A)> As described above, the polycarbonate resin (A) constituting the thermoplastic resin composition of the present invention contains the repeating unit (a) represented by the following general formula (1) and the repeating unit (b) represented by the following general formula (2).

[0025] [ka]

[0026] [ka]

[0027] In the above formulas (1) and (2), X and Y are at least one selected from a single bond, an oxygen atom, a sulfur atom, and a divalent organic group (excluding unsubstituted groups). Rx and Ry are each independently an alkyl group having 1 to 6 carbon atoms.

[0028] (Repeating unit (a)) The repeating unit (a) of the polycarbonate resin (A) of the present invention is represented by the following formula (1).

[0029] [ka]

[0030] In formula (1), X represents at least one selected from a single bond, an oxygen atom, a sulfur atom, and a divalent organic group (excluding unsubstituted groups).

[0031] The divalent organic group for X is not particularly limited, and suitable examples include organic groups represented by the following formula (3).

[0032] [ka]

[0033] In formula (3), R1 and R2 each independently represent a hydrogen atom, a monovalent hydrocarbon group having 1 to 24 carbon atoms, or an alkoxy group having 1 to 24 carbon atoms. R1 and R2 may be bonded to each other to form a ring. Among the above, R1 and R2 are preferably monovalent hydrocarbon groups having 1 to 24 carbon atoms. Examples of the monovalent hydrocarbon group having 1 to 24 carbon atoms include an alkyl group having 1 to 24 carbon atoms, an alkenyl group having 2 to 24 carbon atoms, an aryl group having 6 to 24 carbon atoms which may have a substituent, and an arylalkyl group having 7 to 24 carbon atoms.

[0034] Examples of the alkyl group having 1 to 24 carbon atoms include linear and branched alkyl groups and alkyl groups containing an alicyclic structure. Of these, linear or branched alkyl groups having 1 to 12 carbon atoms or alkyl groups containing an alicyclic structure having 1 to 12 carbon atoms are preferred, and linear alkyl groups having 1 to 12 carbon atoms are particularly preferred. Examples of the alkyl group having 1 to 12 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, and an n-octyl group.

[0035] Examples of the alkenyl group having 2 to 24 carbon atoms include linear and branched alkenyl groups, and alkenyl groups partially containing an alicyclic structure, among which linear alkenyl groups are preferred. Examples of such alkenyl groups having 2 to 24 carbon atoms include vinyl, n-propenyl, n-butenyl, n-pentenyl, n-hexenyl, n-heptenyl, and n-octenyl groups.

[0036] Examples of the aryl group having 6 to 24 carbon atoms include aryl groups which may have a substituent such as an alkyl group, such as a phenyl group, a naphthyl group, a methylphenyl group, a dimethylphenyl group, and a trimethylphenyl group. Examples of the arylalkyl group having 7 to 24 carbon atoms include a benzyl group.

[0037] Examples of the alkoxy group having 1 to 24 carbon atoms include linear, branched, and partially alicyclic alkoxy groups, with linear alkoxy groups being preferred. Specific examples include methoxy, ethoxy, propoxy, and butoxy groups.

[0038] When R1 and R2 are bonded to each other to form a ring, the number of carbon atoms therein is not particularly limited, but is usually 5 to 20, and preferably 6 to 12. When R1 and R2 are bonded to each other to form a ring, examples thereof include cycloalkylidene groups, more specifically, cyclopentylidene groups, cyclohexylidene groups, cycloheptylidene groups, etc. These substituents may be further substituted with a monovalent hydrocarbon group having 1 to 12 carbon atoms.

[0039] Among these, X is more preferably a single bond, a methylene group, an ethylidene group, an isopropylidene group, or a cyclohexyl group which may have a substituent. Liden From the viewpoint of improving heat resistance and suppressing the occurrence of discoloration, an isopropylidene group and a cyclohexyl group are preferred. Liden group, and most preferably an isopropylidene group (i.e., in the above formula (3), R1 , R 2 are all methyl groups).

[0040] In the above formula (1), Rx and Ry are each independently an alkyl group having 1 to 6 carbon atoms, and from the viewpoint of mechanical properties, an alkyl group having 1 to 4 carbon atoms is more preferable, an alkyl group having 1 or 2 carbon atoms is even more preferable, and a methyl group is particularly preferable.

[0041] As described above, a preferred embodiment is 2,2-bis(3-methyl-4-hydroxyphenyl)propane (bisphenol C) in which X is an isopropylidene group and Rx and Ry are both methyl groups, or 2,2-bis(3-methyl-4-hydroxyphenyl)propane (bisphenol C) in which X is cyclohexyl Liden The repeating unit is a repeating unit obtained from 1,1-bis(4-hydroxy-3-methylphenyl)cyclohexane in which the groups Rx and Ry are all methyl groups, and among these, 2,2-bis(3-methyl-4-hydroxyphenyl)propane (bisphenol C) is particularly preferred.

[0042] (Repeating unit (b)) The repeating unit (b) of the polycarbonate resin (A) of the present invention is represented by the following formula (2).

[0043] [ka]

[0044] In formula (2), Y represents at least one selected from a single bond, an oxygen atom, a sulfur atom, and a divalent organic group (excluding unsubstituted groups).

[0045] The divalent organic group for Y is not particularly limited, and examples thereof include organic groups represented by the following formula (4).

[0046] [ka]

[0047] In formula (4), R3 and R4 each independently represent a hydrogen atom, a monovalent hydrocarbon group having 1 to 24 carbon atoms, or an alkoxy group having 1 to 24 carbon atoms. R3 and R4 may be bonded to each other to form a ring. Among the above, R3 and R4 are preferably monovalent hydrocarbon groups having 1 to 24 carbon atoms. Examples of the monovalent hydrocarbon group having 1 to 24 carbon atoms include an alkyl group having 1 to 24 carbon atoms, an alkenyl group having 2 to 24 carbon atoms, an aryl group having 6 to 24 carbon atoms which may have a substituent, and an arylalkyl group having 7 to 24 carbon atoms.

[0048] Examples of the alkyl group having 1 to 24 carbon atoms include linear and branched alkyl groups, alkyl groups having a partial cyclic structure, etc. Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, an n-octyl group, etc.

[0049] Examples of the alkenyl group having 2 to 24 carbon atoms include linear and branched alkenyl groups, and alkenyl groups partially containing an alicyclic structure, among which linear alkenyl groups are preferred. Examples of such alkenyl groups having 2 to 24 carbon atoms include vinyl, n-propenyl, n-butenyl, n-pentenyl, n-hexenyl, n-heptenyl, and n-octenyl groups.

[0050] Examples of the aryl group having 6 to 24 carbon atoms include aryl groups which may have a substituent such as an alkyl group, such as a phenyl group, a naphthyl group, a methylphenyl group, a dimethylphenyl group, and a trimethylphenyl group. Examples of the arylalkyl group having 7 to 24 carbon atoms include a benzyl group.

[0051] Examples of the alkoxy group having 1 to 24 carbon atoms include linear, branched, and partially alicyclic alkoxy groups, with linear alkoxy groups being preferred. Specific examples include methoxy, ethoxy, propoxy, and butoxy groups.

[0052] When R3 and R4 are bonded to each other to form a ring, the number of carbon atoms therein is not particularly limited, but is usually 5 to 20, and preferably 6 to 12. When R3 and R4 are bonded to each other to form a ring, examples thereof include a cycloalkylidene group, more specifically a cyclopentylidene group, a cyclohexylidene group, and a cycloheptylidene group. These substituents may be further substituted with a monovalent hydrocarbon group having 1 to 12 carbon atoms.

[0053] Among these, Y is more preferably an alkyl group having 1 to 10 carbon atoms, and even more preferably a hydrocarbon group having 1 to 8 carbon atoms. Y may also be a hydrocarbon group having 1 or 2 carbon atoms, or a methyl group. An example of such a repeating unit (b) is 2,2-bis(4-hydroxyphenyl)propane (bisphenol A). From the viewpoint of heat resistance, it is preferable that R3 and R4 are bonded to each other to form a ring, that is, the repeating unit (b) is preferably represented by the following formula (6).

[0054] [ka]

[0055] In the formula (6), R5s each independently represent an alkyl group having 1 to 4 carbon atoms, and n is an integer of 0 to 3.

[0056] In the formula (6), specific examples of the alkyl group having 1 to 4 carbon atoms for R5 include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, etc. Among these, R5 is preferably a methyl group.

[0057] In the formula (6), n is an integer of 0 to 3. There are no particular limitations on n as long as it is an integer of 0 to 3, but n is preferably 0 or 3, and particularly preferably n is 3.

[0058] Among these, the repeating unit (b) is particularly preferably 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane (bisphenol TMC) represented by the structure of the following formula (5) from the viewpoint of improving color tone.

[0059] [ka]

[0060] The polycarbonate resin (A) may contain one or more structural units (c) other than the repeating units (a) and (b) within the scope of the present invention. Other structural units (c) include, for example, structural units derived from aromatic dihydroxy compounds such as 4,4'-dihydroxybiphenyl (biphenol) and 6,6'-dihydroxy-3,3,3',3'-tetramethyl-1,1'-spirobiindane (SBI), among which repeating units derived from bisphenol A and biphenol are preferred.

[0061] The polycarbonate resin (A) constituting the thermoplastic resin composition of the present invention contains the repeating unit (a) and the repeating unit (b), thereby improving heat resistance, low dielectric properties, and compatibility with the polyester resin (B). The sum of the contents of the repeating units (a) and the repeating units (b) is preferably 50 mol% or more, more preferably 70 mol% or more, even more preferably 80 mol% or more, and particularly preferably 90 mol% or more, of all carbonate structural units in the polycarbonate resin (A).

[0062] Furthermore, the molar ratio of repeating unit (a) to repeating unit (b) is not particularly limited as long as it is within a range in which the effects of the present invention are achieved, but it is preferable that (a):(b) is in the range of 95:5 to 40:60, more preferably in the range of 90:10 to 45:55, and even more preferably in the range of 85:15 to 50:50. Since the repeating unit (b) of the polycarbonate resin (A) tends to be compatible with the 1,4-cyclohexanedimethanol unit of the polyester resin (B), when the molar ratio of the repeating unit (b) is equal to or greater than the lower limit, the compatibility between the polycarbonate resin (A) and the polyester resin (B) is good. In addition, when the molar ratio of the repeating unit (a) to the repeating unit (b) is within the above range, it is also preferable from the viewpoints of heat resistance and low dielectric properties.

[0063] The molecular weight of the polycarbonate resin (A) is not particularly limited, but the viscosity-average molecular weight (Mv) calculated from the solution viscosity is preferably 10,000 to 35,000. If the viscosity-average molecular weight of the polycarbonate resin (A) is equal to or greater than the lower limit, the relative dielectric constant and dielectric loss tangent of the thermoplastic resin composition of the present invention will be low, which is preferable. If the viscosity-average molecular weight of the polycarbonate resin (A) is equal to or less than the upper limit, the flowability of the thermoplastic resin composition of the present invention will be good, which is also preferable. From this perspective, the viscosity-average molecular weight (Mv) of the polycarbonate resin (A) is more preferably 12,000 or more, even more preferably 13,000 or more, and particularly preferably 14,000 or more. It is also more preferably 30,000 or less, even more preferably 28,000 or less, and particularly preferably 26,000 or less.

[0064] The viscosity average molecular weight (Mv) of the polycarbonate resin (A) is the value calculated from the Schnell viscosity equation, i.e., η = 1.23 × 10-4 Mv0.83, by measuring the intrinsic viscosity (η) (unit: dL / g) at 20°C using an Ubbelohde viscometer with methylene chloride as the solvent. The intrinsic viscosity (η) is also calculated from the specific viscosity (ηsp) measured at each solution concentration (C) (g / dL) using the following equation:

[0065]

number

[0066] <Polyester resin (B)> The polyester resin (B) constituting the thermoplastic resin composition of the present invention must contain 50 mol% or more of 1,4-cyclohexanedimethanol units as a diol component. Since 1,4-cyclohexanedimethanol units tend to be compatible with the repeating units (b) of the polycarbonate resin (A), containing 50 mol% or more of 1,4-cyclohexanedimethanol units can improve compatibility with the polycarbonate resin (A). The content of 1,4-cyclohexanedimethanol units is preferably 55 mol% or more, more preferably 60 mol% or more, even more preferably 65 mol% or more, and particularly preferably 70 mol% or more. There is no particular upper limit, and the content of 1,4-cyclohexanedimethanol units may be 100 mol%.

[0067] The diol component of the polyester resin (B) may contain a diol component other than the above-mentioned 1,4-cyclohexanedimethanol (hereinafter sometimes referred to as "other diol component") as a copolymerization component, and examples thereof include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, 1,3-propanediol, 2,4-dimethyl-2-ethylhexane-1,3-diol, 2-methyl-1,3-propanediol, 2,2-dimethyl-1,3-propanediol (neopentyl glycol), 2-ethyl-2-butyl-1,3-propanediol, 2-ethyl-2-isobutyl-1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-butanediol, 1,6-butanediol, 1,7-butanediol, 1,8-butanediol, 1,9-butanediol, 1,10-butanediol, 1,11-butanediol, 1,12-butanediol, 1,13-butanediol, 1,14-butanediol, 1,15-butanediol, 1,16-butanediol, 1,17-butanediol, 1,18-butanediol, 1,19-butanediol, 1,20-butanediol, 1,21-butanediol, 1,22-butanediol, 1,23-butanediol, 1,24-butanediol, 1,25-butanediol, 1,26-butanediol, 1,27-butanediol, 1,28-butanediol, 1,29-butanediol, 1,30-butanediol, 1,31-butanediol, 1,32-butanediol, 1,33-butanediol, aliphatic diols such as 1,5-pentanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, and 2,2,4-trimethyl-1,6-hexanediol; alicyclic diols such as 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, spiroglycol, tricyclodecane dimethanol, adamantanediol, and 2,2,4,4-tetramethyl-1,3-cyclobutanediol; and aromatic diols such as 4,4'-thiodiphenol, 4,4'-methylenediphenol, 4,4'-dihydroxybiphenyl, o-, m-, and p-dihydroxybenzene, 2,5-naphthalenediol, p-xylenediol, and their ethylene oxide and propylene oxide adducts. Of these, the other diol component is preferably an alicyclic diol from the viewpoint of improving mechanical properties and heat resistance. Furthermore, these other diol components may be used singly or in combination of two or more. The content of the other diol component is preferably 45 mol% or less, more preferably 40 mol% or less, even more preferably 35 mol% or less, and even more preferably 30 mol% or less, and the other diol component may not be contained.

[0068] The dicarboxylic acid component of the polyester resin (B) is not particularly limited, and examples thereof include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, benzylmalonic acid, diphenic acid, 4,4'-oxydibenzoic acid, and naphthalenedicarboxylic acid; aliphatic dicarboxylic acids such as malonic acid, dimethylmalonic acid, succinic acid, glutaric acid, adipic acid, trimethyladipic acid, pimelic acid, 2,2-dimethylglutaric acid, azelaic acid, sebacic acid, fumaric acid, maleic acid, itaconic acid, thiodipropionic acid, and diglycolic acid; and alicyclic dicarboxylic acids such as 1,3-cyclopentanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 2,5-norbornanedicarboxylic acid, and adamantanedicarboxylic acid. Among these, terephthalic acid is preferred from the viewpoint of imparting mechanical strength such as heat resistance, and the terephthalic acid unit preferably comprises 50 mol% or more. The content of the terephthalic acid unit is more preferably 70 mol% or more, further preferably 90 mol% or more, and may be 100 mol% (only terephthalic acid). When a dicarboxylic acid other than terephthalic acid is used as a copolymerization component, an aromatic dicarboxylic acid other than terephthalic acid is preferred, and isophthalic acid is particularly preferred.

[0069] <Contents of Component (A) and Component (B)> The content of the polycarbonate resin (A) in the total amount of resin components in the thermoplastic resin composition of the present invention is preferably 10 to 80 mass %, and the content of the polyester resin (B) is preferably in the range of 20 to 90 mass %. When the contents of the components (A) and (B) are within the above ranges, compatibility is improved, and a resin composition having high heat resistance and low dielectric properties is easily obtained. From the above viewpoints, the content of component (A) is more preferably in the range of 15 to 70 mass%, and even more preferably in the range of 20 to 65 mass%, and the content of component (B) is more preferably in the range of 30 to 85 mass%, and even more preferably in the range of 35 to 80 mass%.

[0070] The resin component in the thermoplastic resin composition of the present invention may contain resins and additives other than the polycarbonate resin (A) and polyester resin (B) as long as the effects of the present invention are not impaired. However, the amount of such resins and additives is usually preferably 10% by mass or less, and more preferably 5% by mass or less. Examples of the additives include recycled resins generated from trimming losses such as selvage, inorganic particles such as silica, talc, kaolin, and calcium carbonate, pigments such as titanium oxide and carbon black, flame retardants, weather-resistant stabilizers, heat-resistant stabilizers, antistatic agents, melt viscosity modifiers, crosslinking agents, lubricants, nucleating agents, plasticizers, antioxidants, antioxidants, light stabilizers, ultraviolet absorbers, neutralizing agents, anti-fogging agents, anti-blocking agents, slip agents, and colorants, which are added for the purpose of improving and adjusting molding processability, productivity, and various physical properties of the porous film.

[0071] <Glass transition temperature (Tg)> The thermoplastic resin composition of the present invention preferably has a glass transition temperature (Tg) of 110°C or higher. (Hereinafter, this may be simply referred to as "glass transition temperature" or "Tg.") Tg is an index of heat resistance, and a Tg of 110°C or higher provides sufficient heat resistance. When there are multiple Tgs, it is preferable that all of them are 110°C or higher. Furthermore, the higher the heat resistance, the more preferable it is, with a Tg of 115°C or higher being even more preferable, and a Tg of 120°C or higher being particularly preferable. Furthermore, the thermoplastic resin composition of the present invention preferably has a single glass transition temperature (Tg), which means that the polycarbonate resin (A) and the polyester resin (B) are highly compatible with each other. Therefore, it is particularly preferable that the thermoplastic resin composition of the present invention has a single Tg and that the Tg is 120°C or higher. The Tg value is measured by the method described in the examples.

[0072] [film] The thermoplastic resin composition of the present invention can be molded into a film, and such a film is also an embodiment of the present invention (hereinafter referred to as "the film of the present invention"). The film of the present invention can be obtained by subjecting the thermoplastic resin composition of the present invention to a general molding method, such as extrusion molding, injection molding, blow molding, vacuum molding, pressure molding, press molding, etc. In each molding method, the apparatus and processing conditions are not particularly limited. The film of the present invention may be a single layer or a multilayer film, and when it is a multilayer film, a conventionally known method can be used as the manufacturing method. The film of the present invention may be an unstretched film or a uniaxially or biaxially stretched film. When stretched, the film is stretched in the longitudinal direction (MD) of the film and in the transverse direction (TD) perpendicular thereto, usually by 1.1 to 6.0 times in at least one direction, preferably by 1.1 to 6.0 times in each of the longitudinal and transverse directions, from the viewpoints of stretching effect, film strength, etc.

[0073] As the biaxial stretching method, any of the conventionally known stretching methods can be used, such as tenter-type sequential biaxial stretching, tenter-type simultaneous biaxial stretching, and tubular-type simultaneous biaxial stretching. For example, in the case of the tenter-type sequential biaxial stretching method, the unstretched film can be produced by heating the unstretched film to a temperature range of Tg to Tg + 50°C relative to the glass transition temperature (Tg) of the resin composition, stretching it 1.1 to 6.0 times in the longitudinal direction using a roll-type longitudinal stretching machine, and then stretching it 1.1 to 6.0 times in the transverse direction using a tenter-type transverse stretching machine within a temperature range of Tg to Tg + 50°C. In addition, in the case of the tenter-type simultaneous biaxial stretching method or tubular-type simultaneous biaxial stretching method, the film can be produced by simultaneously stretching it 1.1 to 6.0 times in both the longitudinal and transverse directions within a temperature range of Tg to Tg + 50°C.

[0074] The biaxially stretched film stretched by the above method is preferably subsequently heat-set. Heat-setting can impart dimensional stability at room temperature. In this case, the treatment temperature is preferably selected from the range of Tm-1 to Tm-50°C, where Tm is the crystalline melting temperature of the resin composition. If the heat-setting temperature is within the above range, heat-setting is sufficiently carried out, stress during stretching is alleviated, sufficient heat resistance and mechanical properties are obtained, and an excellent film can be obtained without problems such as breakage or whitening of the film surface. In the film of the present invention, in order to alleviate the stress of crystallization shrinkage due to heat setting, it is preferable to perform relaxation in the width direction during heat setting by 0 to 15%, preferably 3 to 10%. If relaxation is performed sufficiently and uniformly in the width direction of the film, the shrinkage rate in the width direction becomes uniform, and a film with excellent dimensional stability at room temperature can be obtained. Furthermore, since relaxation follows the shrinkage of the film, there is no sagging of the film, no flapping in the tenter, and no breakage of the film.

[0075] The thickness of the film of the present invention is preferably 1 to 500 μm, more preferably 5 to 300 μm, and even more preferably 10 to 250 μm. By making it 1 μm or more, the film strength is kept within a practical range, and by making it 500 μm or less, it can be suitably used for optical applications, etc. The thickness of the film can be adjusted by adjusting the stretching conditions, etc. The thickness can be measured using a 1 / 1000 mm dial gauge, etc.

[0076] The haze value of the film of the present invention is preferably 5.0% or less, more preferably 4.0% or less, even more preferably 3.0% or less, and particularly preferably 2.5% or less, for a film with a thickness of 200 μm. If the haze value of the present film is equal to or less than the above upper limit, the film has sufficient transparency for use as a film. The haze value was measured by the method described in the examples.

[0077] The dielectric loss tangent of the film of the present invention at a measurement frequency of 10 GHz is preferably less than 0.006, more preferably less than 0.0055, even more preferably less than 0.005, and particularly preferably less than 0.0045. When it is less than the upper limit, the film has excellent electrical properties and is useful as a material for, for example, electronic devices that require high-speed information communication.

[0078] [Application] The thermoplastic resin composition of the present invention has good compatibility between the polycarbonate resin (A) and the polyester resin (B), high heat resistance, transparency, and excellent low dielectric properties, and is therefore suitable for use as a member of a communication device that transmits and receives radio waves in the high frequency band. Specific examples of the communication device components include housings for communication devices such as notebook computers, tablet terminals, smartphones, and router devices that have built-in microwave and / or millimeter wave antennas, and antenna substrate materials for base station substrates, router substrates, server substrates, and CPU substrates. [Example]

[0079] The present invention will now be described in more detail with reference to examples, although the present invention is not limited to the examples described below.

[0080] <Evaluation method> (1) Glass transition temperature Using a viscoelasticity spectrometer DVA-200 (manufactured by IT Measurement & Control Co., Ltd.), the peak temperature of the main dispersion of the loss tangent (tanδ) was measured using temperature dispersion measurement of dynamic viscoelasticity at a strain of 0.1%, a frequency of 10 Hz, and a heating rate of 3°C / min in accordance with JIS K7244 (1999). The heat resistance was evaluated according to the following criteria, with the peak temperature being the glass transition temperature. 〇(good): Peak temperature is 120℃ or higher △ (fair): Peak temperature is 110℃ or more and less than 120℃ ×(pооr); Glass transition temperature is less than 110℃ When there were multiple glass transition temperatures, the lowest glass transition temperature was selected and evaluated according to the above criteria.

[0081] (2) Dielectric tangent The dielectric loss tangent in the in-plane direction of the film was measured at 23°C using a cavity resonator method, and the measurement frequency was 10 GHz, and the evaluation was based on the following criteria. The dielectric properties were evaluated according to the following criteria. ○(good); Dielectric tangent is less than 0.005 △ (fair): Dielectric tangent is 0.005 or more and less than 0.006 ×(pооr); Dielectric tangent is 0.006 or more

[0082] (3) Haze The haze was measured in accordance with JIS K 7136 using a haze meter ("NDH 7000II" manufactured by Nippon Denshoku Industries Co., Ltd.). The transparency was evaluated as follows: a haze of less than 5% was rated as ○ (good), and a haze of 5% or more was rated as × (poor).

[0083] <Material> (Polycarbonate resin (A)) (A-1): Polycarbonate resin copolymerized with bisphenol C and bisphenol TMC, synthesized according to Preparation Example 1 below, a copolymer of bisphenol C:bisphenol TMC = 60:40 (molar ratio) (A-2): Polycarbonate resin copolymerized with bisphenol C and bisphenol TMC, synthesized according to Preparation Example 2 below, a copolymer of bisphenol C:bisphenol TMC = 80:20 (molar ratio) (A-3): Polycarbonate resin copolymerized with 1,1-bis(4-hydroxy-3-methylphenyl)cyclohexane and bisphenol A, copolymer of dimethylbisphenolcyclohexane:bisphenol A = 48:52 (molar ratio) ("LEXAN DMX1435" manufactured by Sabic) (A-4): Bisphenol C polycarbonate resin ("Novarex MF7526" manufactured by Mitsubishi Engineering Plastics Corporation)

[0084] [Preparation Example 1] A raw material mixture was prepared by adding 67.19 g (approximately 0.263 mol) of 2,2-bis(4-hydroxy-3-methylphenyl)propane (BPC) (manufactured by Honshu Chemical Co., Ltd.), 54.24 g (0.175 mol) of 4,4'-(3,3,5-trimethylcyclohexylidene)bisphenol (BP-TMC) (manufactured by Honshu Chemical Co., Ltd.), 96.39 g (approximately 0.450 mol) of diphenyl carbonate (DPC), and a 0.4 mass% aqueous solution of cesium carbonate as a catalyst to a 150 ml glass reactor equipped with a reactor stirrer, a reactor heater, and a reactor pressure regulator.

[0085] Next, the pressure inside the glass reactor was reduced to approximately 50 Pa (0.38 Torr), and then the pressure was returned to atmospheric pressure with nitrogen. This operation was repeated three times to purge the inside of the reactor with nitrogen. After nitrogen purge, the external temperature of the reactor was increased to 220°C, and the internal temperature of the reactor was gradually increased to dissolve the mixture. The stirrer was then rotated at 100 rpm. Then, the pressure inside the reactor was reduced from 101.3 kPa (760 Torr) to 13.3 kPa (100 Torr) absolute over 40 minutes, while distilling off phenol, which was a by-product of the oligomerization reaction of the dihydroxy compound and DPC inside the reactor.

[0086] Next, the pressure inside the reactor was maintained at 13.3 kPa, and a transesterification reaction was carried out for 80 minutes while further distilling off phenol. The temperature outside the reactor was then raised to 250°C, and the pressure inside the reactor was reduced from 13.3 kPa (100 Torr) to 399 Pa (3 Torr) absolute over 40 minutes, and the distilled phenol was removed from the system. The temperature outside the reactor was then raised to 285°C, and the absolute pressure inside the reactor was reduced to 30 Pa (approximately 0.2 Torr), and a polycondensation reaction was carried out. The polycondensation reaction was terminated when the reactor's agitator reached a predetermined stirring power.

[0087] Next, the reactor was pressurized to 101.3 kPa absolute pressure with nitrogen, and then the gauge pressure was increased to 0.2 MPa, and the polycarbonate resin was extracted in the form of strands from the bottom of the reactor, and the strand-like polycarbonate resin was then pelletized using a rotary cutter to obtain polycarbonate resin (A-1). The viscosity average molecular weight (Mv) of the obtained polycarbonate resin (A-1) was 22,000.

[0088] [Preparation Example 2] Polycarbonate resin (A-2) was obtained by the same synthesis method as in Preparation Example 1, except that the amount of 2,2-bis(4-hydroxy-3-methylphenyl)propane (BPC) (manufactured by Honshu Chemical Co., Ltd.) was 89.59 g (approximately 0.350 mol) and the amount of 4,4'-(3,3,5-trimethylcyclohexylidene)bisphenol (BP-TMC) (manufactured by Honshu Chemical Co., Ltd.) was 27.12 g (0.087 mol). The viscosity average molecular weight (Mv) of the obtained polycarbonate resin (A-2) was 23,000.

[0089] (Polyester resin (B)) (B-1): Polycyclohexanedimethylene terephthalate (SK Chemicals "SKYPURA1631") containing 92 mol% terephthalic acid and 8 mol% isophthalic acid as acid components and 100 mol% 1,4-cyclohexanedimethanol as diol component. (B-2): Polycyclohexanedimethylene terephthalate ("ALTESTER SC" manufactured by Mitsubishi Gas Chemical Company, Inc.) containing 100 mol% of terephthalic acid as the acid component and 14 mol% of spiroglycol and 86 mol% of 1,4-cyclohexanedimethanol as diol components. (B-3): Polycyclohexanedimethylene terephthalate (Eastman "Tritan FX200") containing 100 mol% of terephthalic acid as the acid component and 66 mol% of 1,4-cyclohexanedimethanol and 34 mol% of 2,2,4,4-tetramethyl-1,3-cyclobutanediol as diol components. (B-4): Polyethylene terephthalate containing 100 mol% terephthalic acid as the acid component and 100 mol% ethylene glycol as the diol component ("Novapex GM341" manufactured by Mitsubishi Chemical Corporation) (B-5): Polyethylene terephthalate ("ALTESTER S4500") containing 100 mol% terephthalic acid as the acid component and 52 mol% ethylene glycol, 5 mol% diethylene glycol, and 43 mol% spiroglycol as diol components.

[0090] Examples 1 to 8, Comparative Examples 1 to 5, and Reference Examples 1 to 5 <Preparation of Resin Composition and Film> The raw materials were dry-blended according to the composition shown in Table 1, fed to a Plastograph Mixer manufactured by Toyo Seiki Seisaku-sho, and melt-kneaded for 5 minutes at a temperature of 280°C and a rotation speed of 40 rpm to obtain a resin composition. The resin composition was sandwiched between two metal plates and press-molded at a temperature of 280°C, a pressure of 3 MPa, and a molding time of 10 seconds, and then rapidly cooled to 100°C or below with water to obtain a resin sheet with a thickness of 200 μm. The obtained resin sheet was evaluated as described above. The results are shown in Table 1.

[0091] [Table 1]

[0092] The results in Table 1 show that the thermoplastic resin compositions of Examples 1 to 8 had a single Tg of 110°C or higher. This indicates that the polycarbonate resin (A) and the polyester resin (B) have good compatibility and high heat resistance. In particular, the thermoplastic resin compositions of Examples 1 to 7 had a Tg of 120°C or higher, demonstrating excellent heat resistance. On the other hand, the thermoplastic resin compositions of Comparative Examples 1, 2, 4, and 5 exhibited two Tg values, indicating insufficient compatibility between the polycarbonate resin (A) and the polyester resin (B).Furthermore, the thermoplastic resin compositions of Comparative Examples 1, 2, and 4 exhibited Tg values ​​of 110°C or less, indicating insufficient heat resistance. Furthermore, the films made of the thermoplastic resin compositions of Examples 1 to 8 have low dielectric loss tangents and small haze values, which indicates that the films of the present invention have excellent electrical properties and high transparency. On the other hand, the films made of the thermoplastic resin compositions of Comparative Examples 1 to 5 have high haze values ​​and are therefore insufficient in transparency. [Industrial Applicability]

[0093] As described above, the thermoplastic resin composition of the present invention and the film made of the thermoplastic resin composition have high heat resistance, excellent low dielectric properties, and high transparency, and are therefore very useful in optical film applications that require low dielectric properties.

Claims

1. A thermoplastic resin composition comprising: a polycarbonate resin (A) which contains a repeating unit (a) represented by the following general formula (1) and a repeating unit (b) represented by the following general formula (2), wherein the molar ratio of the repeating unit (a) to the repeating unit (b) is 85:15 to 40:60, and the sum of the contents of the repeating units (a) and the repeating units (b) in all carbonate structural units of the polycarbonate resin (A) is 80 mol % or more; and a polyester resin (B) which contains 50 mol % or more of 1,4-cyclohexanedimethanol units as a diol component. 【Chemical 1】 【Chemistry 2】 [In formula (1), X is an isopropylidene group or a cyclohexylidene group which may be substituted with a monovalent hydrocarbon group having 1 to 12 carbon atoms. Rx and Ry are each a methyl group. In formula (2), when X is an isopropylidene group, Y is a cyclohexylidene group which may be substituted with an alkyl group having 1 to 12 carbon atoms, and when X is a cyclohexylidene group which may be substituted with a monovalent hydrocarbon group having 1 to 12 carbon atoms, Y is an isopropylidene group.]

2. The thermoplastic resin composition according to claim 1, wherein in formula (2), Y is a cyclohexylidene group optionally substituted with a methyl group when X is an isopropylidene group, and Y is an isopropylidene group when X is a cyclohexylidene group optionally substituted with a methyl group.

3. The thermoplastic resin composition according to claim 1, wherein X in formula (1) is an isopropylidene group or a cyclohexylidene group.

4. The thermoplastic resin composition according to any one of claims 1 to 3, further comprising an alicyclic diol other than 1,4-cyclohexanedimethanol as a diol component of the polyester resin (B).

5. 5. The thermoplastic resin composition according to claim 1, wherein the polyester resin (B) contains 50 mol % or more of terephthalic acid units as a dicarboxylic acid component.

6. The thermoplastic resin composition according to any one of claims 1 to 5, wherein the content of the polycarbonate resin (A) is 10 to 80 mass% and the content of the polyester resin (B) is 20 to 90 mass% in the total amount of resin components.

7. The thermoplastic resin composition according to any one of claims 1 to 6, which has a single glass transition temperature measured in accordance with JIS K7244 (1999).

8. The thermoplastic resin composition according to any one of claims 1 to 7, which has a glass transition temperature of 110°C or higher as measured in accordance with JIS K7244 (1999).

9. A film comprising the thermoplastic resin composition according to any one of claims 1 to 8.

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