JP2023034392A - Polyester resin, film, and laminate - Google Patents

Abstract

To obtain a polyester resin which is excellent in toughness and curling resistance in addition to having low dielectric characteristics at high frequencies when formed into a film.SOLUTION: The polyester resin comprises the following structural unit (I), a p-hydroxybenzoic acid structural unit (II), and a 6-hydroxy-2-naphthoic acid structural unit (III) as essential components. The content of the structural unit (I) is 1-40 mol%. The content molar ratio (=(II)/(III)) of the structural unit (II) to the structural unit (III) is larger than 3.0. (R1 represents any one selected from H, a C1-5 alkyl group, an aryl group and CF3; Ar represents any aromatic ring structure selected from benzene, naphthalene, biphenyl and triphenyl, provided that the aromatic ring may have any substituent selected from a C1-5 alkyl group, an aryl group, a halogen atom and CF3; and X1 and X2 each independently represent any one of O, CO and NH.)SELECTED DRAWING: None

Description

The present invention relates to polyester resins, molded articles, and laminates. More specifically, the present invention relates to polyester resins, polyester resin molded articles such as films and sheets obtained using the polyester resins, and laminates.

With the recent increase in demand for mobile terminals and communication base stations, the demand for resins used in printed circuit boards such as rigid boards and flexible boards is increasing. Furthermore, in recent years, the fifth generation mobile communication "5G" has started to be used, and resins for these substrates are required to have high performance such as low dielectric properties at high frequencies.

As a technique for imparting low dielectric properties to a resin, a technique for suppressing the mobility of the resin when exposed to electromagnetic waves is effective. Liquid crystalline polyester resins are resins with excellent dielectric properties because the mobility of molecular chains is suppressed by arranging and packing the molecular chains due to the liquid crystal structure. As an example of a liquid crystal polyester resin with a further reduced dielectric, a liquid crystal polyester resin having a certain amount of structural units composed of 6-hydroxy-2-naphthoic acid has been proposed (eg, Patent Document 1).

When a resin is used as a printed circuit board such as the rigid board or flexible board described above, the resin is often formed into a film for use, and therefore, it is desired to improve the properties of the film. In particular, it is important to improve film toughness and curl resistance. Devices are becoming smaller and smaller, and printed circuit boards are often placed in tight spaces between electrical and electronic components while being folded. Moreover, when a circuit board is used in a vehicle, it is required to have a property of not deforming even in a high-temperature and high-humidity environment, that is, curl resistance. Various properties of polyester resin films can be improved by copolymerizing specific structures. As an example of improving film properties by introducing a specific structure, in Patent Document 2, a polyarylate resin film composed of bisphenol residues and aromatic dicarboxylic acid residues has excellent heat resistance, light transparency and flame retardancy. Patent document 3 discloses that an aromatic copolyester composed of a bisphenol and a naphthalene structure forms a film having excellent physical properties. Similarly, Patent Document 4 discloses an aromatic polyester having a bisphenol structure, which is said to be easy to mold and have excellent physical properties.

Japanese Patent Application Laid-Open No. 2004-196930 WO2014/024787 JP-A-2-255719 JP-A-6-49189

Although the method described in Patent Document 1 is effective in reducing the dielectric loss tangent of the polyester resin, it is insufficient in low dielectric properties in a high frequency band called millimeter waves, and has a problem in toughness. Patent Documents 2 to 4 describe methods for improving various film properties by copolymerizing a specific structure, but there is no mention of dielectric properties, and the high level required for recent electrical and electronic parts. It has been difficult to achieve both low dielectric properties in the high frequency band of the film and toughness and curl resistance of the film.

An object of the present invention is to provide a polyester resin, a polyester resin composition, a molded article obtained therefrom, and a polyester resin film, which, when formed into a film, have low dielectric properties at high frequencies and are excellent in toughness and curl resistance. is the subject.

As a result of intensive studies to solve the above problems, the present inventors have found that while having a specific structure in the main chain, a structural unit derived from p-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid The inventors have found that a polyester resin containing a specific amount of the derived structural unit has low dielectric properties at high frequencies when formed into a film, and in addition, has excellent toughness and curl resistance, and has reached the present invention.

Accordingly, the present invention is as follows:
(1) A polyester resin containing the following structural unit (I), structural unit (II), and structural unit (III) as essential components, wherein the structural unit (I) is contained relative to 100 mol% of the total structural units of the polyester resin. The amount is 1 to 40 mol%, and the content ratio of structural units (II) and (III) (content (mol%) of (II) with respect to 100 mol% of all structural units of polyester resin / 100 mol of all structural units of polyester resin % of (III) (=(II)/(III))) is greater than 3.0.

(R ¹ represents one selected from a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an aryl group, and a trifluoromethyl group (CF ₃ ); Ar represents benzene, naphthalene, biphenyl, and triphenyl; Represents a selected aromatic ring structure, and these aromatic rings may have substituents of alkyl groups having 1 to 5 carbon atoms, aryl groups, halogen atoms, and trifluoromethyl groups (CF ₃ ). X ¹ and X ² each independently represent one of O, CO and NH.)
(2) The polyester resin according to (1), wherein the polyester resin contains 0.1 to 30 mol % of structural units derived from an aromatic or aliphatic diol with respect to 100 mol % of the total structural units of the polyester resin.
(3) The polyester resin according to (1) or (2), wherein the structural unit (I) is a structural unit shown in (i) below.

(X ¹ and X ² each independently represent O, CO, or NH; R ¹ is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an aryl group, or a trifluoromethyl group (CF ₃ ), R ² and R ³ each independently represent an alkyl group having 1 to 5 carbon atoms, an aryl group, a halogen atom and a trifluoromethyl group (CF ₃ ), n and m each independently represent 0 Represents any integer from ~4.)
(4) A polyester resin film containing the polyester resin described in (1) to (3).
(5) A laminate obtained by laminating a support on at least one surface of the polyester resin film described in (4).

When the polyester resin of the present invention is made into a film, it has low dielectric properties at high frequencies and is excellent in toughness and curl resistance. Films obtained from such resins are suitable for laminates used in electrical/electronic parts, flexible printed wiring boards in mechanical parts, semiconductor packages, and the like.

The present invention will be described in detail below.

<Polyester resin>
A polyester resin is a polymer in which each structural unit is linked via an ester bond. For example, an oxycarbonyl unit, a dioxy unit, a dicarbonyl unit, and the like, which will be described later, are selected as the structural unit.

Next, structural units constituting the polyester resin will be described.

The polyester resin of the present invention contains structural unit (I) as an essential component.

(R ¹ represents one selected from a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an aryl group, and a trifluoromethyl group (CF ₃ ); Ar represents benzene, naphthalene, biphenyl, and triphenyl; represents any selected aromatic ring structure, and these aromatic rings have a substituent of an alkyl group having 1 to 5 carbon atoms, an aryl group, a halogen atom, and a trifluoromethyl group (CF ₃ ); X ¹ and X ² each independently represent any one of O, CO and NH.)

Structural unit (I) has a trifluoromethyl group (CF ₃ ). Fluorine atoms have high electronegativity and have the effect of attracting surrounding electrons and suppressing electron mobility. Therefore, the presence of the structural unit (I) in the main chain results in low dielectric properties at high frequencies. In addition, the fluorine atom has a larger atomic radius than the hydrogen atom, and the presence of the trifluoromethyl group in the center of the propane structure of the structural unit (I) suppresses the rotation of the propane structure due to steric hindrance, making it more rigid. structure. Furthermore, the bending structure derived from propane alleviates the formation of highly linear long chains generated by structural units derived from aromatic hydroxycarboxylic acids, which will be described later, and suppresses the formation of foreign substances derived from such sites, resulting in toughness and resistance. A polyester resin having excellent curling property can be obtained.

R ¹ in structural unit (I) can be selected from a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an aryl group, and a trifluoromethyl group. Therefore, a trifluoromethyl group is preferred.

The content of the structural unit (I) is 1 to 40 mol% with respect to 100 mol% of the total structural units of the polyester resin. Below 1 mol %, the dielectric properties and toughness at high frequencies are degraded. If it is more than 40 mol %, the resistance to heat is lowered and the curling resistance is lowered. From the viewpoint of dielectric properties and toughness at high frequencies, it is preferably 5 mol % or more, more preferably 8 mol % or more, and even more preferably 12 mol % or more. From the viewpoint of enhancing curl resistance, it is preferably 35 mol % or less, more preferably 32 mol % or less, and even more preferably 28 mol % or less.

From the viewpoint of facilitating the introduction of the structural unit (I) into the main chain, the structural unit (I) is preferably a structural unit shown in (i) below.

(X ¹ and X ² each independently represent O, CO, or NH; R ¹ is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an aryl group, or a trifluoromethyl group (CF ₃ Each of R ² and R ³ independently represents an alkyl group having 1 to 5 carbon atoms, an aryl group, a halogen atom, or a trifluoromethyl group (CF ₃ ), n, m each independently represents an integer from 0 to 4.)
Structural unit (I) is, for example, 2,2-bis(4-hydroxyphenyl)hexafluoropropane, 2,2-bis(4-carboxyphenyl)hexafluoropropane, 2,2-bis(4-aminophenyl) Hexafluoropropane, 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane, 4,4'-(hexafluoroisopropylidene)diphthalic anhydride, 4,4'-(hexafluoroisopropylidene) Bis(1,2-benzenedicarboxylic acid), 1,1,1-trifluoro-2,2-bis(4-hydroxyphenyl)propane, 1,1,1-trifluoro-2,2-bis(4- hydroxyphenyl)ethane, etc. can be introduced as a monomer. 2,2-bis(4-hydroxyphenyl)hexafluoropropane, 2,2-bis(4-carboxyphenyl)hexafluoropropane, 2,2-bis(4-aminophenyl) from the viewpoint of polymerizability and dielectric properties at high frequencies ) It is preferable to use hexafluoropropane as a monomer, and it is particularly preferable to use 2,2-bis(4-hydroxyphenyl)hexafluoropropane as a monomer.

The polyester resin of the present invention contains structural units (II) and (III) derived from the following aromatic hydroxycarboxylic acid as essential units as oxycarbonyl units, and the content ratio of the structural units (II) and (III) ( Content (mol%) of (II) with respect to 100 mol% of the total structural units of the polyester resin/Content (mol%) of (II) with respect to 100 mol% of the total structural units of the polyester resin (hereinafter referred to as "(II)/(III )”) is greater than 3.0.

(II) and (III) are structural units derived from p-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid, respectively. When the value of (II)/(III) is less than 3.0, the toughness and curl resistance of the resulting film are lowered. From the viewpoint of further improving toughness and heat resistance, the value of (II)/(III) is preferably 5.0 or more, more preferably 8.0 or more, and particularly preferably 10.0 or more. In addition, although there is no upper limit to the value of (II)/(III), it is preferably 100 or less, more preferably 90 or less, from the viewpoint of suppressing the formation of foreign substances derived from the long chain of (II) and achieving high toughness. 80 or less is particularly preferred.
The content of the structural unit (II) with respect to 100 mol % of the total structural units of the polyester resin is preferably 30 mol % or more from the viewpoint of low dielectric properties at high frequencies, toughness and curl resistance. It is more preferably 35 mol % or more, more preferably 40 mol % or more, even more preferably 45 mol % or more, and particularly preferably 50 mol % or more. Moreover, it is preferably 80 mol % or less, more preferably 77 mol % or less, even more preferably 75 mol % or less, and particularly preferably 72 mol % or less.

The content of the structural unit (III) with respect to 100 mol % of the total structural units of the polyester resin is preferably 0.1 mol % or more from the viewpoint of low dielectric properties at high frequencies, toughness and curl resistance. 0.5 mol % or more is more preferable, 1 mol % or more is still more preferable, and 1.2 mol % or more is particularly preferable. Also, it is preferably 30 mol % or less, more preferably 25 mol % or less, even more preferably 20 mol % or less, and particularly preferably 10 mol % or less.

The polyester resin of the present invention may contain a structural unit derived from an aromatic or aliphatic diol as a dioxy unit different from the structural unit (I), and the dioxy unit is 0.1 per 100 mol % of the total structural units of the polyester resin. It is preferably ~30 mol %. Within this range, it is possible to reduce the generation of infusible foreign matter derived from the long chain of the structural unit (II) or (III), and to further improve the toughness of a polyester resin film. 0.5 mol % or more is preferable, 1 mol % or more is preferable, and 1.2 mol % or more is more preferable. From the viewpoint of curl resistance, the content is preferably 25 mol % or less, more preferably 22 mol % or less, even more preferably 20 mol % or less, and particularly preferably 18 mol % or less.

Specific examples of aromatic or aliphatic diols include 4,4′-dihydroxybiphenyl, hydroquinone, resorcinol, t-butylhydroquinone, phenylhydroquinone, chlorohydroquinone, 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 3 ,4'-dihydroxybiphenyl, 2,2-bis(4-hydroxyphenyl)propane, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxydiphenyl sulfone, 4,4'-dihydroxydiphenyl sulfide, 4,4' - Structural units derived from aromatic diols such as dihydroxybenzophenone, structural units derived from 2,2'-bis(4-hydroxyphenyl)propane, ethylene glycol, propylene glycol, 1,4-butanediol, 1,6- Structural units generated from aliphatic diols such as hexanediol and neopentyl glycol, and structural units generated from alicyclic diols such as 1,4-cyclohexanediol and 1,4-cyclohexanedimethanol. Structural units formed from 4,4'-dihydroxybiphenyl, hydroquinone, and ethylene glycol are preferred from the viewpoints of good polymerizability, low dielectric properties at high frequencies, and toughness and curl resistance. Note that these structural units may be used in combination.

The polyester resin of the present invention can contain a structural unit derived from a dicarbonyl unit different from the structural unit (I). Specific examples of dicarbonyl units include terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 4,4′-diphenyldicarboxylic acid, 3,3′-diphenyldicarboxylic acid, 2,2′-diphenyldicarboxylic acid, Aromas such as 1,2-bis(phenoxy)ethane-4,4'-dicarboxylic acid, 1,2-bis(2-chlorophenoxy)ethane-4,4'-dicarboxylic acid, 4,4'-diphenyletherdicarboxylic acid Structural units generated from group dicarboxylic acids, structural units generated from aliphatic dicarboxylic acids such as adipic acid, azelaic acid, sebacic acid, dodecanedioic acid, hexahydroterephthalic acid, 1,4-cyclohexanedicarboxylic acid, 1,3- Examples include structural units generated from alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid. From the viewpoints of good polymerizability, low dielectric properties at high frequencies, and excellent toughness and curl resistance, structural units generated from aromatic dicarboxylic acids are preferable, and among them, generated from terephthalic acid, isophthalic acid, and 2,6-naphthalenedicarboxylic acid. Structural units are particularly preferred.

In addition to the structural units described above, the polyester resin may further contain structural units formed from p-aminobenzoic acid, p-aminophenol, etc., as long as the properties are not impaired.

The raw material monomers constituting each structural unit are not particularly limited as long as they have a structure capable of forming each structural unit. In addition, acylated products of hydroxyl groups of such monomers, esterified products of carboxyl groups, acid halides, carboxylic acid derivatives such as acid anhydrides, and the like may also be used.

A method for calculating the content of each structural unit in the polyester resin is shown below. First, after pulverizing the polyester resin, tetramethylammonium hydroxide is added, and the pyrolysis GC/MS measurement is performed using Shimadzu's GCMS-QP5050A. The content of structural units not detected or below the detection limit is calculated as 0 mol %.

The melting point (Tm) of the polyester resin is preferably 350° C. or less from the viewpoint that it is easy to form a film by the method described later, has low dielectric properties at high frequencies, and is excellent in curl resistance. , 340° C. or lower, and particularly preferably 330° C. or lower.

The melting point (Tg) of the polyester resin is preferably 110° C. or higher, more preferably 120° C. or higher, and even more preferably 130° C. or higher, from the viewpoint of low dielectric properties at high frequencies and excellent curl resistance. The melting point (Tg) of the polyester resin is preferably 200° C. or lower, more preferably 190° C. or lower, still more preferably 180° C. or lower, and most preferably 170° C. or lower, from the viewpoint of facilitating film formation by the method described later.

<Method for producing polyester resin>
The method for producing the polyester resin used in the present invention is not particularly limited, and it can be produced according to a known polyester polycondensation method. Specifically, structural units derived from p-hydroxybenzoic acid, structural units derived from 6-hydroxy-2-naphthoic acid, structural units derived from 2,2-bis(4-hydroxyphenyl)hexafluoropropane, Taking a polyester resin composed of structural units derived from 4,4′-dihydroxybiphenyl, structural units derived from terephthalic acid, and structural units derived from ethylene glycol, the following methods can be mentioned.

(1) p-acetoxybenzoic acid, 6-acetoxy-2-naphthoic acid, 2,2-bis(4-acetoxyphenyl)hexafluoropropane, 4,4′-diacetoxybiphenyl, terephthalic acid, and polyethylene terephthalate— A method for producing a polyester resin from a polyester polymer or oligomer such as bis(β-hydroxyethyl) terephthalate by a deacetic acid polycondensation reaction.

(2) p-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid, 2,2-bis(4-hydroxyphenyl)hexafluoropropane, 4,4'-dihydroxybiphenyl, terephthalic acid, and polyethylene terephthalate A method for producing a polyester resin by reacting a polyester polymer or oligomer such as bis(β-hydroxyethyl) terephthalate with acetic anhydride to acetylate the phenolic hydroxyl groups, followed by a deacetic acid polycondensation reaction.

(3) A method using 1,2-bis(6-hydroxy-2-naphthoyl)ethane as a part of the starting material in the production method of (1) or (2).

Among them, the method (2) is easy to control the degree of polymerization of the polyester resin, and can suppress the long chain of the above-mentioned aromatic hydroxycarboxylic acid (structural unit (II) or (III)). It is preferably used because it is superior in terms of

When the polyester resin of the present invention is produced by the method (2), the temperature of the reaction for acetylating the phenolic hydroxyl group (acetylation reaction) is usually in the range of 130 to 210°C, preferably 130 to 210°C. It is in the range of 150°C. The acetylation reaction time is usually 30 minutes or more from the viewpoint of polymerization reactivity, but the above-mentioned aromatic hydroxycarboxylic acid (structural unit (II) or (III)) can suppress the long chain and has a high elastic modulus. And from the viewpoint of high strength and improved film formability, the temperature is preferably 130 to 150° C. for 2 hours or more, more preferably 2 hours and 30 minutes or more. On the other hand, the acetylation reaction time is usually 6 hours or less from the viewpoint of productivity, but is preferably 4 hours or less, more preferably 3 hours and 30 minutes or less, from the viewpoint of achieving high elastic modulus and high strength.

From the viewpoint of polymerization reactivity, the amount of acetic anhydride used in the acetylation reaction is usually at least 1.00 equivalents of the total phenolic hydroxyl groups in the polyester raw material. 1.08 equivalents or more are preferable, and 1.10 equivalents or more are more preferable from the viewpoint of reducing the amount of divalent hydroxyl groups and providing low dielectric properties at high frequencies. On the other hand, the amount of acetic anhydride to be used is usually 1.20 equivalents or less, preferably 1.14 equivalents or less, more preferably 1.13 equivalents or less, from the viewpoint of suppressing foreign substances derived from chains of aromatic hydroxycarboxylic acids. more preferred.

As a method for producing the polyester resin used in the present invention, it is also possible to complete the polycondensation reaction by a solid phase polymerization method. Examples of solid-phase polymerization treatment include the following methods. First, a polyester resin polymer or oligomer is pulverized by a pulverizer. The pulverized polymer or oligomer is heated under a stream of nitrogen or under reduced pressure to polycondense to the desired degree of polymerization to complete the reaction. The heating is preferably carried out at a melting point of -50°C to -5°C for 1 to 50 hours.

The polycondensation reaction of polyester resin proceeds without a catalyst, but stannous acetate, tetrabutyl titanate, potassium acetate and sodium acetate, antimony trioxide, metal magnesium, etc. can also be used as catalysts.

<Polyester resin molded product>
The polyester resin of the present invention can be processed into molded articles having excellent surface appearance (color tone), mechanical properties, and heat resistance by conventional molding methods such as injection molding, extrusion molding, press molding, solution casting film formation, and spinning. It is possible to The molded products here include injection molded products, extrusion molded products, press molded products, sheets, pipes, various films such as unstretched films, uniaxially stretched films, biaxially stretched films, unstretched yarns, super stretched yarns, etc. Examples include various fibers. A film is preferable from the viewpoint that the effects of the polyester resin of the present invention, which has low dielectric properties at high frequencies and excellent toughness and curl resistance, can be remarkably obtained. A method for manufacturing the film will be described later.

<Polyester resin film and laminate>
The polyester resin of the present invention can be used as a raw material for producing polyester resin films and laminates.

The polyester resin film of the present invention contains the polyester resin of the present invention. The method for producing the polyester resin film is not particularly limited, and it can be produced using a known method, for example, it can be obtained by the methods described in (I) and (II) below.

(I) The polyester resin of the present invention is extruded into a film form from, for example, a single-screw extruder, a twin-screw extruder, a vent extruder, a tandem extruder, etc., through an inflation die, a T-die, etc. and solidified to obtain a film. Method.

(II) A polyester resin composition obtained by dispersing or dissolving the polyester resin of the present invention in a medium such as an organic solvent is applied on a support, and the medium is removed to obtain a laminate. a method of removing a support from a laminated laminate.

It is also possible to stretch the films obtained from techniques such as (I) and (II). The stretching method is not particularly limited, and either sequential biaxial centrifugation or simultaneous biaxial centrifugation may be used. A draw ratio of 2 to 8 times and a draw rate of 500 to 5000%/min are often used.

Films obtained from techniques such as (I) and (II) are preferably subjected to a heat treatment. By performing the heat treatment, the higher-order structure of the polyester resin constituting the film settles into a thermodynamically stable structure, and various properties are improved. The heat treatment temperature is appropriately determined according to the properties, but the melting point (Tm) of the polyester resin is preferably in the range of -5°C to +30°C, more preferably in the range of ±0°C to +20°C.

Further, the laminate of the present invention is a laminate obtained by laminating a support and a resin layer, wherein the support is laminated on at least one surface of the resin layer containing the polyester resin of the present invention. . The laminate can be produced, for example, by the following methods (III) to (VI).

(III) A method of attaching the film produced by the above method (I) or (II) to a support by thermocompression bonding.

(IV) A method of adhering the film produced by the method (I) or (II) above to a support with an adhesive.

(V) A method of forming a support on the film produced by the above method (I) or (II) by vapor deposition.

(VI) A method of coating a support with a polyester resin composition obtained by dispersing or dissolving the polyester resin of the present invention in a medium such as an organic solvent, and then removing the solvent.

The support used in the above methods (II) to (VI) is not particularly limited, and is selected from metal foils, glass substrates, polymer films, and the like. It is important that the supports used in methods (II) and (III) are resistant to the solvents used. The support may be a single substance such as a metal foil, a glass substrate, a polymer film, or a composite material thereof. Polymer films include insulating polyimide films, liquid crystal polyester films, cycloolefin polymer films, and polypropylene films.

Examples of metals used in the methods (III) to (VI) when the support is a metal layer include gold, silver, copper, nickel, and aluminum. Copper is preferred for circuit board applications such as flexible printed wiring boards and rigid printed wiring boards in electrical/electronic parts and mechanical parts.

Examples of the structure of the laminate thus obtained include a two-layer structure of a film and a support, a three-layer structure in which a support is laminated on both sides of a film, and a three-layer structure in which a film is laminated on both sides of a support. A layered structure, and a multi-layered structure in which four or more layers of films and supports are alternately laminated can be mentioned.

The laminate obtained by the above method is, for example, a circuit such as a flexible printed wiring board or a rigid printed wiring board on which electrical/electronic components, such as various computers, OA equipment, and AV equipment, or electrical/electronic components are mounted. Substrates: semiconductor packages used for automobile semiconductors, industrial semiconductors, etc.; base materials for transparent conductive films, base materials for polarizing films, packaging films for cooking foods and microwave oven heating, electromagnetic wave shielding films, antibacterial properties It can be used for films, films for gas separation, and the like. Since the resin layer has a low dielectric loss tangent at high temperatures and a high elastic modulus and a low coefficient of linear expansion, it is easy to obtain a laminate with suppressed transmission loss and deformation at high temperatures. It is suitably used for circuit boards such as flexible printed wiring boards and rigid printed wiring boards in electric/electronic parts and mechanical parts, and semiconductor packages.

EXAMPLES The present invention will be described below using examples, but the present invention is not limited by the examples. In the examples, the composition and property evaluation of the polyester resin were measured by the following methods.

(1) Composition analysis of polyester resin To 0.1 mg of pulverized polyester resin, 2 μL of tetramethylammonium hydroxide 25% methanol solution is added, and pyrolysis GC / MS measurement is performed using Shimadzu GCMS-QP5050A. The content (mol%) of each structural unit with respect to 100 mol% of the total structural units of and the ratio (%) of the following structural unit (II) in all structural units derived from aromatic hydroxycarboxylic acid were calculated.

(2) Measurement of melting point (Tm) and glass transition temperature (Tg) of polyester Polyester resin was heated from room temperature at 20°C/min using a differential scanning calorimeter (DSC) device (Q200 manufactured by TA Instruments). After observing the endothermic peak temperature (Tm ₁ ) observed at the time, it was held at a temperature of Tm ₁ +20 ° C. for 5 minutes, then cooled once to room temperature under a temperature decrease condition of 20 ° C./min, and again increased by 20 ° C./min. The endothermic peak temperature in the temperature rise curve observed when heated under high temperature conditions is the melting point (Tm), and the intermediate value of the two bending point temperatures derived from the glass transition is obtained, and this is the glass transition temperature (Tg). and

[Example 1]
870 parts by weight of p-hydroxybenzoic acid, 85 parts by weight of 6-hydroxy-2-naphthoic acid, 2,2-bis(4-hydroxyphenyl)hexafluoropropane 605 were placed in a 5 L reaction vessel equipped with a stirring blade and a distillation tube. 299 parts by weight of terephthalic acid and 1162 parts by weight of acetic anhydride (1.1 equivalents of the total phenolic hydroxyl groups) were charged and reacted at 145°C for 150 minutes with stirring under a nitrogen gas atmosphere. °C over 4 hours. After that, the polymerization temperature was maintained at 300° C., the pressure was reduced to 1.0 mmHg (133 Pa) over 1.0 hour, and the reaction was continued until the torque required for stirring reached 50 kg·cm to complete the polymerization. Next, the inside of the reaction vessel is pressurized to 2.5 kg/cm ² (0.25 MPa), and the polymer is discharged in strands through a mouthpiece having a circular discharge port with a diameter of 6 mm, and pelletized by a cutter to obtain polyester. A resin (A-1) was obtained.

A composition analysis of this polyester resin (A-1) revealed that the structural unit derived from p-hydroxybenzoic acid (structural unit (II)) was 60.9 mol%, derived from 6-hydroxy-2-naphthoic acid. The structural unit (structural unit (III)) is 4.3 mol%, the structural unit (structural unit (I)) derived from 2,2-bis(4-hydroxyphenyl)hexafluoropropane is 17.4 mol%, Structural units derived from terephthalic acid accounted for 17.4 mol %. Also, Tm was 265°C and Tg was 132°C.

The obtained polyester resin (A-1) pellets were pulverized by a coarse pulverizer to obtain a powder. The obtained powder was press-molded (molding time: 5 minutes, molding pressure: 10 MPa) using a 37t manual hot press (Shindo Kinzoku Kogyo NF-37HH) with the mold temperature set to 300 ° C. A film of -1 was obtained. The obtained film was heat-treated in a hot air oven at 255° C. for 4 hours in a nitrogen atmosphere to obtain a film with a thickness of 0.08 mm.

[Example 2]
870 parts by weight of p-hydroxybenzoic acid, 85 parts by weight of 6-hydroxy-2-naphthoic acid, and 666 parts of 2,2-bis(4-hydroxyphenyl)hexafluoropropane were placed in a 5 L reaction vessel equipped with a stirring blade and a distillation tube. Parts by weight, 404 parts by weight of terephthalic acid, 84 parts by weight of 4,4'-dihydroxybiphenyl and 1304 parts by weight of acetic anhydride (1.1 equivalents of the total phenolic hydroxyl groups) were charged and heated to 145°C under a nitrogen gas atmosphere with stirring. After reacting for 150 minutes, the temperature was raised from 145° C. to 300° C. over 4 hours. After that, the polymerization temperature was maintained at 300° C., the pressure was reduced to 1.0 mmHg (133 Pa) over 1.0 hour, and the reaction was continued until the torque required for stirring reached 50 kg·cm to complete the polymerization. Next, the inside of the reaction vessel is pressurized to 2.5 kg/cm ² (0.25 MPa), and the polymer is discharged in strands through a mouthpiece having a circular discharge port with a diameter of 6 mm, and pelletized by a cutter to obtain polyester. A resin (A-2) was obtained.

A composition analysis of this polyester resin (A-2) revealed that the structural unit derived from p-hydroxybenzoic acid (structural unit (II)) was 54.3 mol%, derived from 6-hydroxy-2-naphthoic acid. The structural unit (structural unit (III)) is 3.9 mol%, the structural unit (structural unit (I)) derived from 2,2-bis(4-hydroxyphenyl)hexafluoropropane is 17.1 mol%, Structural units derived from 4,4'-dihydroxybiphenyl (structural units derived from aromatic diol) accounted for 3.9 mol%, and structural units derived from terephthalic acid accounted for 20.8 mol%. Also, Tm was 267°C and Tg was 135°C.

The obtained polyester resin (A-2) pellets were pulverized by a coarse pulverizer to obtain a powder. The obtained powder was press-molded (molding time: 5 minutes, molding pressure: 10 MPa) using a 37t manual hot press (Shindo Kinzoku Kogyo NF-37HH) with the mold temperature set to 300 ° C. A -2 film was obtained. The obtained film was heat-treated in a hot air oven at 255° C. for 4 hours in a nitrogen atmosphere to obtain a film with a thickness of 0.08 mm.

[Example 3]
870 parts by weight of p-hydroxybenzoic acid, 85 parts by weight of 6-hydroxy-2-naphthoic acid, and 378 parts by weight of 2,2-bis(4-hydroxyphenyl)hexafluoropropane were placed in a 5 L reaction vessel equipped with a stirring blade and a distillation tube. Parts by weight, 374 parts by weight of terephthalic acid, 210 parts by weight of 4,4'-dihydroxybiphenyl and 1263 parts by weight of acetic anhydride (1.1 equivalents of the total phenolic hydroxyl groups) were charged and heated to 145°C under a nitrogen gas atmosphere with stirring. After reacting for 150 minutes, the temperature was raised from 145° C. to 300° C. over 4 hours. After that, the polymerization temperature was maintained at 300° C., the pressure was reduced to 1.0 mmHg (133 Pa) over 1.0 hour, and the reaction was continued until the torque required for stirring reached 50 kg·cm to complete the polymerization. Next, the inside of the reaction vessel is pressurized to 2.5 kg/cm ² (0.25 MPa), and the polymer is discharged in strands through a mouthpiece having a circular discharge port with a diameter of 6 mm, and pelletized by a cutter to obtain polyester. A resin (A-3) was obtained.

A composition analysis of this polyester resin (A-3) revealed that the structural unit derived from p-hydroxybenzoic acid (structural unit (II)) was 56.0 mol%, derived from 6-hydroxy-2-naphthoic acid. The structural unit (structural unit (III)) is 4.0 mol%, the structural unit (structural unit (I)) derived from 2,2-bis(4-hydroxyphenyl)hexafluoropropane is 10.0 mol%, Structural units derived from 4,4′-dihydroxybiphenyl (structural units derived from aromatic diol) accounted for 10.0 mol %, and structural units derived from terephthalic acid accounted for 20.0 mol %. Also, Tm was 263°C and Tg was 123°C.

The obtained polyester resin (A-3) pellets were pulverized with a coarse pulverizer to obtain powder. The obtained powder was press-molded (molding time: 5 minutes, molding pressure: 10 MPa) using a 37t manual hot press (Shindo Kinzoku Kogyo NF-37HH) with the mold temperature set to 300 ° C. A -3 film was obtained. The obtained film was heat-treated in a hot air oven at 255° C. for 4 hours in a nitrogen atmosphere to obtain a film with a thickness of 0.08 mm.

[Example 4]
970 parts by weight of p-hydroxybenzoic acid, 220 parts by weight of 6-hydroxy-2-naphthoic acid, and 472 parts by weight of 2,2-bis(4-hydroxyphenyl)hexafluoropropane were placed in a 5 L reaction vessel equipped with a stirring blade and a distillation tube. Parts by weight, 233 parts by weight of terephthalic acid and 1235 parts by weight of acetic anhydride (1.1 equivalents of the total phenolic hydroxyl groups) were charged and reacted at 145°C for 150 minutes while stirring under a nitrogen gas atmosphere. °C over 4 hours. After that, the polymerization temperature was kept at 280° C., the pressure was reduced to 1.0 mmHg (133 Pa) over 1.0 hour, the reaction was continued, and the polymerization was completed when the torque required for stirring reached 35 kg·cm. Next, the inside of the reaction vessel is pressurized to 2.0 kg/cm ² (0.20 MPa), and the polymer is discharged in strand form through a mouthpiece having a circular discharge port with a diameter of 6 mm, and pelletized by a cutter to obtain polyester. A resin (A-4) was obtained.

A composition analysis of this polyester resin (A-4) revealed that the structural unit derived from p-hydroxybenzoic acid (structural unit (II)) was 63.8 mol%, derived from 6-hydroxy-2-naphthoic acid. The structural unit (structural unit (III)) is 10.6 mol%, the structural unit (structural unit (I)) derived from 2,2-bis(4-hydroxyphenyl)hexafluoropropane is 12.8 mol%, Structural units derived from terephthalic acid accounted for 12.8 mol %. Also, Tm was 255°C and Tg was 122°C.

The obtained polyester resin (A-4) pellets were pulverized by a coarse pulverizer to obtain a powder. The obtained powder was press molded (molding time: 5 minutes, molding pressure: 10 MPa) using a 37t manual hot press machine (Shindo Kinzoku Kogyo NF-37HH) with the mold temperature set to 280 ° C. A -4 film was obtained. The obtained film was heat-treated in a hot air oven at 245° C. for 4 hours in a nitrogen atmosphere to obtain a film with a thickness of 0.08 mm.

[Example 5]
870 parts by weight of p-hydroxybenzoic acid, 85 parts by weight of 6-hydroxy-2-naphthoic acid, and 988 parts by weight of 2,2-bis(4-carboxyphenyl)hexafluoropropane were placed in a 5 L reaction vessel equipped with a stirring blade and a distillation tube. Parts by weight, 469 parts by weight of 4,4'-dihydroxybiphenyl and 1324 parts by weight of acetic anhydride (1.1 equivalents of the total phenolic hydroxyl groups) were charged and reacted at 145°C for 150 minutes with stirring under a nitrogen gas atmosphere. , from 145° C. to 300° C. over 5.5 hours. After that, the polymerization temperature was maintained at 300° C., the pressure was reduced to 1.0 mmHg (133 Pa) over 1.0 hour, and the reaction was continued until the torque required for stirring reached 45 kg·cm to complete the polymerization. Next, the inside of the reaction vessel is pressurized to 2.0 kg/cm ² (0.20 MPa), and the polymer is discharged in strand form through a mouthpiece having a circular discharge port with a diameter of 6 mm, and pelletized by a cutter to obtain polyester. A resin (A-5) was obtained.

A composition analysis of this polyester resin (A-5) revealed that the structural unit derived from p-hydroxybenzoic acid (structural unit (II)) was 53.4 mol%, derived from 6-hydroxy-2-naphthoic acid. The structural unit (structural unit (III)) is 3.8 mol%, the structural unit (structural unit (I)) derived from 2,2-bis(4-carboxyphenyl)hexafluoropropane is 21.4 mol%, Structural units derived from 4,4′-dihydroxybiphenyl (structural units derived from aromatic diol) accounted for 21.4 mol %. Also, Tm was 262°C and Tg was 130°C.

The obtained polyester resin (A-5) pellets were pulverized by a coarse pulverizer to obtain a powder. The obtained powder was press-molded (molding time: 5 minutes, molding pressure: 10 MPa) using a 37t manual hot press (Shindo Kinzoku Kogyo NF-37HH) with the mold temperature set to 300 ° C. A -5 film was obtained. The obtained film was heat-treated in a hot air oven at 260° C. for 4 hours in a nitrogen atmosphere to obtain a film with a thickness of 0.08 mm.

[Comparative Example 1]
1131 parts by weight of p-hydroxybenzoic acid, 110 parts by weight of 6-hydroxy-2-naphthoic acid, 232 parts by weight of hydroquinone, 350 parts by weight of terephthalic acid and 1419 parts by weight of acetic anhydride were placed in a 5 L reaction vessel equipped with a stirring blade and a distillation tube. (1.07 equivalents of the total phenolic hydroxyl groups) were charged and reacted at 150° C. for 120 minutes while stirring in a nitrogen gas atmosphere, and then the temperature was raised from 150° C. to 360° C. over 4 hours. Thereafter, the polymerization temperature was maintained at 360° C., the pressure was reduced to 1.0 mmHg (133 Pa) over 1.0 hour, and the reaction was continued until the torque required for stirring reached 30 kg·cm, and polymerization was completed. Next, the inside of the reaction vessel is pressurized to 2.0 kg/cm ² (0.20 MPa), and the polymer is discharged in a strand through a mouthpiece having a circular discharge port with a diameter of 6 mm. A resin (A-6) was obtained.

A composition analysis of this polyester resin (A-6) revealed that the structural unit derived from p-hydroxybenzoic acid (structural unit (II)) was 63.1 mol%, derived from 6-hydroxy-2-naphthoic acid. Structural unit (structural unit (III)) is 4.5 mol%, structural unit derived from hydroquinone (structural unit derived from aromatic diol) is 16.2 mol%, and structural unit derived from terephthalic acid is 16.2 mol%. It was 2 mol %. Also, Tm was 330°C and Tg was 120°C.

The obtained polyester resin (A-6) pellets were pulverized by a coarse pulverizer to obtain a powder. The obtained powder was press molded (molding time: 5 minutes, molding pressure: 10 MPa) using a 37t manual hot press machine (Shindo Kinzoku Kogyo NF-37HH) with the mold temperature set to 350 ° C. A -6 film was obtained. The obtained film was heat-treated in a hot air oven at 320° C. for 4 hours in a nitrogen atmosphere to obtain a film with a thickness of 0.08 mm.

[Comparative Example 2]
261 parts by weight of p-hydroxybenzoic acid, 25 parts by weight of 6-hydroxy-2-naphthoic acid, and 2,2-bis(4-hydroxyphenyl)hexafluoropropane 1755 were placed in a 5 L reaction vessel equipped with a stirring blade and a distillation tube. Parts by weight, 867 parts by weight of terephthalic acid and 1362 parts by weight of acetic anhydride (1.07 equivalents of the total phenolic hydroxyl groups) were charged and reacted at 150°C for 120 minutes with stirring under a nitrogen gas atmosphere. °C over 4 hours. After that, the polymerization temperature was maintained at 300° C., the pressure was reduced to 1.0 mmHg (133 Pa) over 1.0 hour, and the reaction was continued until the torque required for stirring reached 35 kg·cm to complete the polymerization. Next, the inside of the reaction vessel is pressurized to 2.0 kg/cm ² (0.20 MPa), and the polymer is discharged in strand form through a mouthpiece having a circular discharge port with a diameter of 6 mm, and pelletized by a cutter to obtain polyester. A resin (A-7) was obtained.

A composition analysis of this polyester resin (A-7) revealed that the structural unit derived from p-hydroxybenzoic acid (structural unit (II)) was 15.1 mol%, derived from 6-hydroxy-2-naphthoic acid. The structural unit (structural unit (III)) is 1.1 mol%, the structural unit (structural unit (I)) derived from 2,2-bis(4-hydroxyphenyl)hexafluoropropane is 41.9 mol%, Structural units derived from terephthalic acid accounted for 41.9 mol%. Moreover, Tm was not observed, and Tg was 180°C.

The obtained polyester resin (A-7) pellets were pulverized by a coarse pulverizer to obtain a powder. The obtained powder was press molded (molding time: 5 minutes, molding pressure: 10 MPa) using a 37t manual hot press machine (Shindo Kinzoku Kogyo NF-37HH) with the mold temperature set to 260 ° C. A -7 film was obtained. The obtained film was heat-treated in a hot air oven at 190° C. for 4 hours in a nitrogen atmosphere to obtain a film with a thickness of 0.08 mm.

[Comparative Example 3]
1106 parts by weight of p-hydroxybenzoic acid, 579 parts by weight of 6-hydroxy-2-naphthoic acid and 207 parts by weight of 2,2-bis(4-hydroxyphenyl)hexafluoropropane were placed in a 5 L reaction vessel equipped with a stirring blade and a distillation tube. Parts by weight, 102 parts by weight of terephthalic acid and 1346 parts by weight of acetic anhydride (1.07 equivalents of the total phenolic hydroxyl groups) were charged and reacted at 150°C for 120 minutes with stirring under a nitrogen gas atmosphere. °C over 4 hours. After that, the polymerization temperature was kept at 300° C., the pressure was reduced to 1.0 mmHg (133 Pa) over 1.0 hour, and the reaction was continued until the torque required for stirring reached 40 kg·cm to complete the polymerization. Next, the inside of the reaction vessel is pressurized to 2.0 kg/cm ² (0.20 MPa), and the polymer is discharged in strand form through a mouthpiece having a circular discharge port with a diameter of 6 mm, and pelletized by a cutter to obtain polyester. A resin (A-8) was obtained.

Composition analysis of this polyester resin (A-8) revealed that the structural unit derived from p-hydroxybenzoic acid (structural unit (III)) was 65.0 mol%, derived from 6-hydroxy-2-naphthoic acid. The structural unit (structural unit (II)) is 25.0 mol%, the structural unit (structural unit (I)) derived from 2,2-bis(4-hydroxyphenyl)hexafluoropropane is 5.0 mol%, Structural units derived from terephthalic acid accounted for 5.0 mol %. Also, Tm was 235°C and Tg was 118°C.

The obtained polyester resin (A-8) pellets were pulverized with a coarse pulverizer to obtain powder. The obtained powder was press molded (molding time: 5 minutes, molding pressure: 10 MPa) using a 37t manual hot press machine (Shindo Kinzoku Kogyo NF-37HH) with the mold temperature set to 260 ° C. A -8 film was obtained. The obtained film was heat treated in a hot air oven at 225° C. for 4 hours in a nitrogen atmosphere to obtain a film with a thickness of 0.08 mm.

Table 1 shows the results of the evaluations (3) to (5) below for the polyester resin films obtained in Examples 1 to 5 and Comparative Examples 1 to 3. In addition, the content (mol%) of the structural unit (I) relative to 100 mol% of the total structural units of the <1> polyester resin obtained by the composition analysis of the polyester resins described in Examples 1 to 4 and Comparative Examples 1 to 3 ), <2> content (mol%) of structural units derived from p-hydroxybenzoic acid (structural unit (II)) relative to 100 mol% of all structural units of polyester resin, <3> 100 total structural units of polyester resin Content (mol%) of structural unit (structural unit (III)) derived from 6-hydroxy-2-naphthoic acid relative to mol%, <4> 4,4-dihydroxybiphenyl relative to 100 mol% of all structural units of polyester resin Or content (mol%) of structural units derived from hydroquinone (aromatic diol), <5> Content (mol%) of structural units derived from terephthalic acid (dicarbonyl unit) relative to 100 mol% of all structural units of polyester resin , <6> Content ratio of structural unit (structural unit (II)) derived from p-hydroxybenzoic acid and structural unit (structural unit (III)) derived from 6-hydroxy-2-naphthoic acid (polyester resin overall structure The results of the content (mol%) of (II) with respect to 100 mol% of units/content (mol%) of (III) with respect to 100 mol% of all polyester resin structural units (= (II)/(III))) are also shown. 1.

(3) Evaluation of Dielectric Properties at High Frequency For the polyester resin films obtained in each example and comparative example, a 10 mm square film-shaped sample for evaluation was produced. Using the obtained film for dielectric property evaluation, a cut-off cylindrical waveguide method (JIS R1660-1 (2004)) is performed using a network analyzer N5227A manufactured by Keysight Technologies Inc. and SUM-CYLINDER Ver2 manufactured by Samtec Co., Ltd. The dielectric constant at 23° C. and 65 GHz was determined by The smaller the dielectric constant value, the better the dielectric properties at high frequencies.

(4) Toughness evaluation For the polyester resin films obtained in each example and comparative example, samples were cut into strips having a length of 150 mm and a width of 10 mm. The distance between chucks was 50 mm and the tensile speed was 200 mm/min. Measurement was performed five times according to the method specified in JIS K 7127 (1999), and the average value of the tensile elongation at break (%) was calculated. The higher the value, the better the toughness.

(5) Curling resistance The polyester resin films obtained in each example and comparative example were superimposed on a copper foil (12 µm thick) and pressed (1 MPa) for 5 minutes at a temperature of +20°C to produce a copper-clad laminate. got The resulting copper-clad laminate was cut into pieces having a width of 20 cm and a length of 20 cm. Ten of them were treated at 210° C. for 3 hours and allowed to stand at room temperature for 1 hour to obtain a copper-clad laminate for curl resistance measurement. The obtained copper-clad laminate for curl resistance measurement was placed on a platen with the copper plate facing upward, and the maximum average height (mm) of the protrusions was defined as the amount of thermal deformation and measured. The smaller the amount of heat deformation (mm), the better the curl resistance is evaluated, and the copper-clad laminate for curl resistance measurement is deformed to the extent that it cannot be measured, such as curling into a cylinder, or the polyester When the resin film melted or flowed and could not maintain a uniform film shape, it was evaluated as "not measurable" and markedly inferior in curl resistance.

When the polyester resin of the present invention is formed into a film, it has low dielectric properties at high frequencies, and is excellent in toughness and curl resistance. The polyester resin film and laminate of the present invention are suitable for use in circuit boards such as flexible printed wiring boards and rigid printed wiring boards using laminates characterized by laminating a plurality of sheets, and semiconductor packages.

Claims (5)

A polyester resin comprising the following structural unit (I), structural unit (II), and structural unit (III) as essential components, wherein the content of the structural unit (I) is 1 relative to 100 mol% of the total structural units of the polyester resin ~ 40 mol%, the content ratio of structural units (II) and (III) (content (mol%) of (II) relative to 100 mol% of all structural units of polyester resin / relative to 100 mol% of all structural units of polyester resin ( A polyester resin in which the content (mol %) of II) (=(II)/(III)) is greater than 3.0.

(R ¹ represents one selected from a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an aryl group, and a trifluoromethyl group (CF ₃ ); Ar represents benzene, naphthalene, biphenyl, and triphenyl; represents any selected aromatic ring structure, and these aromatic rings are any substituent selected from alkyl groups having 1 to 5 carbon atoms, aryl groups, halogen atoms, and trifluoromethyl groups (CF ₃ ) X ¹ and X ² each independently represent O, CO, or NH.) 2. The polyester resin according to claim 1, wherein the polyester resin contains 0.1 to 30 mol % of structural units derived from an aromatic or aliphatic diol with respect to 100 mol % of all structural units of the polyester resin. 3. The polyester resin according to claim 1 or 2, wherein the structural unit (I) is a structural unit shown in (i) below.

X ¹ and X ² each independently represent O, CO or NH.
R ¹ represents any one selected from a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an aryl group and a trifluoromethyl group (CF ₃ ).
R ² and R ³ each independently represent one selected from an alkyl group having 1 to 5 carbon atoms, an aryl group, a halogen atom and a trifluoromethyl group (CF ₃ ).
n and m each independently represent an integer of 0 to 4; A polyester resin film comprising the polyester resin according to any one of claims 1 to 3. A laminate obtained by laminating a support on at least one surface of the polyester resin film according to claim 4 .