WO2021129394A1 - Polyester resin, polyester resin composition, and molded product thereof - Google Patents

Abstract

The present invention relates to a polyester resin, at least prepared from polymerization of a dicarboxylic acid component and a diol component. The dicarboxylic component contains terephthalic acid and/or a derivative thereof able to form an ester, the diol component contains 1,4-butanediol and a diol having a relatively short side chain. Relative to the total mass of the diol units in the polyester resin, the content of monomeric units originating from the 1,4-butanediol is 70-98 mol%, and the content of monomeric units originating from the diol having a relatively short side chain is 2-30 mon%. The melting point of the polyester resin is 185°C or higher.

Description

Polyester resin, polyester resin composition and molded products thereof Technical field

The invention relates to a polyester resin, a polyester resin composition and a molded product thereof with low dielectric loss.

Background technique

With the rapid development of the microelectronics industry, the size of electronic devices tends to be miniaturized, and the wiring density of transistors has risen sharply. Negative effects such as signal interference between lines, resistance and capacitance (RC) delays, and increased heat generation per unit area of the circuit board have occurred. , There is a demand for the development of high-efficiency, high-speed, low-energy consumption, and multi-functional electronic products. From a technical point of view, in order to meet the needs of high-speed data transmission brought about by the high frequency of communication, a high-performance substrate that can greatly reduce the loss of transmission signals is essential. Smaller dielectric loss is conducive to greatly reducing the signal loss in high-frequency communication propagation. Therefore, in order to reduce signal transmission loss, materials with low dielectric loss must be used for the substrate.

Recently, various polymer materials have been widely developed and researched as low-dielectric loss materials. Researches are mostly focused on polyimide, polyaryl ether ketone, polybenzoxazole, liquid crystal polymer, etc. These materials have high mechanical strength because of the large number of aromatic rings in the main chain structure, but they have melting The problem is difficult to process. Therefore, there are requirements for the development of polyester resins with excellent melt processability and low dielectric loss.

In recent years, there has been a lot of research and development on polyester resins, but there is no report on the use of copolymerization modification methods to reduce the dielectric loss of polyester resins.

Patent Document 1 (Chinese Patent Document CN102585180A) discloses a 2,3-butanediol modified polyester resin with high molecular weight and high glass transition temperature, but it has the problem of low crystallinity, so it still exists The problem of large dielectric loss.

Patent Document 2 (Chinese Patent Document CN101831057A) discloses a 1,3-butanediol modified polybutylene terephthalate/polytrimethylene terephthalate copolymer with good dyeing properties, but this modification Polyester resin has the problem of low crystallinity, so there is still the problem of large dielectric loss.

Patent Document 3 (Japanese Patent Document 2014-218652A) discloses a 2-methyl-1,3-propanediol modified polybutylene terephthalate resin with rapid melting properties, but the modified polyester resin is Low melting point and low crystallinity, so there is still the problem of large dielectric loss.

Summary of the invention

In view of the above-mentioned problems, the object of the present invention is to provide a polyester resin with low dielectric loss, a composition containing the polyester resin, and a molded product thereof.

After intensive research, the inventors found that by adjusting the content of monomer units derived from 1,4-butanediol and side chain-containing monomer units derived from the diol represented by the following formula 1 in the polyester resin, The crystallinity of the polyester resin can be maintained, and the molecular movement in the amorphous region can be suppressed, so that a polyester resin with small dielectric loss can be prepared, and the object of the present invention can be achieved.

That is, in order to achieve the above-mentioned object, the present invention has the following configuration.

The polyester resin of the present invention is prepared by polymerizing at least a dicarboxylic acid component and a diol component; wherein the dicarboxylic acid component contains terephthalic acid and/or its ester-forming derivatives, and the diol component Contains 1,4-butanediol and the diol represented by formula 1; relative to the total amount of monomer units derived from the diol component in the polyester resin, monomer units derived from 1,4-butanediol The content of is 70-98 mol%, and the content of monomer units derived from the diol shown in Formula 1 is 2-30 mol%; the melting point Tm of the polyester resin is 185°C or higher.

【Formula 1】

The above formula 1 satisfies any one of the following conditions (A) to (D).

(A), n is an integer of 1 to 4, R1 and R2 are hydrogen elements, and R3 is an aliphatic hydrocarbon group with 1 to 6 carbon atoms;

(B), n is an integer from 0 to 4, R2 is a hydrogen element, and R1 and R3 are independently an aliphatic hydrocarbon group with 1 to 6 carbon atoms;

(C), n is an integer from 1 to 4, R1 and R3 are hydrogen elements, R2 is independently a hydrogen element or an aliphatic hydrocarbon group with 1 to 6 carbon atoms, wherein at least one of R2 is a carbon atom number 1. ～6 aliphatic hydrocarbon group;

(D), n is 0, R1 is a hydrogen element, and R3 is an aliphatic hydrocarbon group with 2-8 carbon atoms.

In the present invention, the diol represented by Formula 1, for example, the diol that satisfies the condition (A) includes 1,3-butanediol, 1,3-pentanediol, 1,3-hexanediol, 1,3-Heptanediol, 1,4-pentanediol, 1,5-hexanediol; diols satisfying condition (B) include 2,3-butanediol and 2,3-pentanediol , 2,3-hexanediol, 2,3-heptanediol, 2,3-octanediol, 3,4-hexanediol, 3,4-heptanediol, 3,4-octanediol, 4 ,5-octanediol, 2,4-pentanediol, 2,4-hexanediol, 2,4-octanediol, 3,5-heptanediol, 2,5-hexanediol, 2,5 -Heptanediol, 2,5-octanediol, 3,6-octanediol, 1,5-hexadiene-3,4-diol, etc.; diols satisfying condition (C) include 2- Methyl-1,3-propanediol, 2-ethyl-1,3-propanediol, 2-propyl-1,3-propanediol, 2-isopropyl-1,3-propanediol, 2-methylene-1 ,3-Propanediol; Diols satisfying condition (D) include 1,2-butanediol, 1,2-pentanediol, 1,2-hexanediol, 1,2-heptanediol, 1, 2-octanediol, 1,2-decanediol, 3,3-dimethyl-1,2-butanediol, 7-octene-1,2-diol, 3-butene-1,2 -Diol, etc.

For the diol structure shown in Formula 1, if n is an integer of 5 or more, or for any of the conditions (A), (B), and (C), where R1, R2, and R3 of an aliphatic hydrocarbon group are used When any one of them has 7 or more carbon atoms, or when R3 is an aliphatic hydrocarbon group with 9 or more carbon atoms for condition (D), the crystallinity of the polyester resin will decrease, which will cause its dielectric loss to change. Big. N in Formula 1 that satisfies the condition (A) or (C) is preferably an integer of 1-3, and more preferably an integer of 1-2. N in Formula 1 that satisfies the condition (B) is preferably an integer of 0 to 3, and more preferably an integer of 0 to 2. In addition, with regard to Formula 1 satisfying any of the conditions (A), (B), and (C), any of R1, R2, and R3 is preferably an aliphatic hydrocarbon group having 1 to 5 carbon atoms, It is more preferably an aliphatic hydrocarbon group having 1 to 3 carbon atoms. R3 in Formula 1 that satisfies the condition (D) is preferably an aliphatic hydrocarbon group having 2 to 6 carbon atoms, and more preferably an aliphatic hydrocarbon group having 2 to 4 carbon atoms.

The diol component used in the present invention includes 1,4-butanediol and the diol represented by Formula 1 above. In addition, as the diol component of the present invention, one or more selected from the diols listed below can also be included. Specifically, the following examples can be listed but not limited to the following examples: ethylene glycol, 1,3-propanediol , 1,5-pentanediol, 1,6-hexanediol, or aliphatic diols such as decanediol; 1,1-cyclohexanedimethanol, 1,4-cyclohexanediol, 1,4 -Cyclohexane dimethanol, 1,4-dicyclohexane dimethanol, or tricyclodecane dimethanol and other alicyclic diols; benzene dimethanol, bis(p-hydroxy)biphenyl, bis(p-hydroxy)di Phenylpropane, 2,2-bis[4-(2-hydroxyethoxy)phenyl]propane, bis[4-(2-hydroxyethoxy)phenyl]sulfone, 1,1-bis[4- (2-Hydroxyethoxy)phenyl]cyclohexane, 4,4-dihydroxyp-terphenyl, or 4,4-dihydroxyp-tetraphenyl and other aromatic diols; the diol can also be acetyl It is used in the form of a chemical compound or an alkali metal salt.

In the present invention, the content of the 1,4-butanediol-derived monomer unit is 70-98 mol% with respect to the total amount of the diol component-derived monomer unit in the polyester resin. Furthermore, from the viewpoint of improving the crystallinity of the polyester resin, the lower limit of the content of the 1,4-butanediol-derived monomer unit is preferably 80 mol% or more, and more preferably 85 mol% or more. On the other hand, from the viewpoint of reducing the dielectric loss tangent value, the upper limit is preferably 96 mol% or less.

Furthermore, in the present invention, the content of the monomer unit derived from the diol represented by the above formula 1 is 2-30 mol% with respect to the total amount of the monomer unit derived from the diol component in the polyester resin. Further, from the viewpoint of suppressing the molecular mobility of the amorphous region, the content of the monomer unit derived from the diol represented by Formula 1 is preferably 4 mol% or more. On the other hand, from the viewpoint of maintaining the crystallinity of the polyester resin, its content is preferably 20 mol% or less, and more preferably 15 mol% or less.

The dicarboxylic acid component used in the present invention contains terephthalic acid and/or its ester-forming derivatives. The derivatives capable of forming esters of terephthalic acid include, for example, alcohol ester derivatives such as dimethyl terephthalate and diethyl terephthalate; other derivatives capable of forming esters such as terephthaloyl chloride. . In addition, as the dicarboxylic acid component of the present invention, one or more selected from the dicarboxylic acid components listed below and their ester-forming derivatives may be included. Specifically, the following examples may be mentioned but not limited to The following examples: isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1 ,5-Naphthalenedicarboxylic acid, 1,8-naphthalenedicarboxylic acid, 4,4'-dicarboxydiphenylmethane, anthracene dicarboxylic acid, 4,4'-diphenyldicarboxylic acid, diphenoxyethyl Aromatic dicarboxylic acid, 4,4'-diphenyl ether dicarboxylic acid, 5-sulfoisophthalic acid, monosodium 5-sulfoisophthalate or sodium 3-sulfoisophthalate, etc. Carboxylic acid; alicyclic dicarboxylic acid such as 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, cyclopentanedicarboxylic acid, or 4,4'-dicyclohexyldicarboxylic acid Acid; aliphatic dicarboxylic acids such as oxalic acid, succinic acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanedione acid, dimer acid, etc.; the above-mentioned dicarboxylic acids correspond to The alkyl diesters and diacid chlorides as monomer raw materials are also exemplified.

The content of monomer units derived from terephthalic acid and/or its ester-forming derivatives is preferably 80 relative to the total amount of monomer units derived from the dicarboxylic acid component in the polyester resin obtained by the present invention. -100mol%, when the content of the monomer unit derived from terephthalic acid and/or its ester-forming derivative is less than 80mol%, the crystallinity of the polyester resin will decrease, and there will be dielectric loss of the polyester resin The tendency to become bigger. In addition, the content of the monomer unit derived from terephthalic acid and/or its ester-forming derivative is preferably 90 mol% or more, and more preferably 95 mol% or more.

The polyester resin of the present invention is prepared from at least the above-mentioned dicarboxylic acid component and diol component, but in addition to the above-mentioned dicarboxylic acid component and diol component, as a monomer of the polyester resin, it may also contain selected from the following Monobasic acid and monohydric alcohol. Specific examples can be listed but not limited to the following examples: acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, heptanoic acid, n-octanoic acid, 2,2-dimethylpropionic acid, 3-methylbutanoic acid, 3 ,3-Dimethyl-1-butyric acid, 4-methylvaleric acid, 3,3-dimethylvaleric acid, 4-methylhexanoic acid, 2,4-dimethylvaleric acid, 3,5- Aliphatic monocarboxylic acids such as dimethylhexanoic acid and phenoxyacetic acid, and their derivatives capable of forming esters; benzoic acid, 4-methylbenzoic acid, 4-tert-butylbenzoic acid, 4-n-propoxy Aromatics such as benzoic acid, 4-n-butoxy benzoic acid, 4-n-hexoxy benzoic acid, 4-octyloxy benzoic acid, 4-phenyl benzoic acid, 4-benzyl benzoic acid, p-chlorobenzoic acid, etc. Monobasic carboxylic acid and its derivatives capable of forming esters; anhydrides of monobasic acids such as acetic anhydride and benzoic anhydride; monohydric alcohols such as butanol, cyclohexanol, and benzyl alcohol. The above monobasic acid or monohydric alcohol may be used alone or in combination of two or more kinds.

Derived from the above 1,4-butanediol and diol components other than the diol represented by formula 1, dicarboxylic acid components other than terephthalic acid and its ester-forming derivatives, monobasic acids, and monohydric alcohols The total content of the monomer units in the polyester resin is preferably 15% by weight or less by weight, more preferably 10% by weight or less, and still more preferably 5% by weight or less.

The melting point (Tm) of the polyester resin of the present invention is 185°C or higher. In the present invention, the melting point of the polyester resin can be measured by the following method: Using a differential scanning calorimeter in a nitrogen atmosphere, the polyester resin is reduced from the molten state to 30°C at a temperature drop rate of 20°C/min, and Keep it at this temperature for 2 minutes, and then increase the temperature at a heating rate of 20°C/min, and measure the endothermic peak temperature that appears during the heating process, which is the melting point of the polyester resin. From the viewpoint of heat resistance and melt processability, the melting point of the polyester resin is preferably 190°C or higher, and more preferably 195°C or higher. In addition, in the case where multiple endothermic peak temperatures occur during the above-mentioned heating process, the highest endothermic peak temperature is taken as the melting point.

The polyester resin in the present invention is reduced from the molten state to 30°C at a temperature drop rate of 20°C/min using a differential scanning calorimeter under a nitrogen atmosphere, and kept at this temperature for 2 minutes, and then at 20°C/min The temperature rise rate of the temperature rise is preferably 30 J/g or more of the endothermic peak heat amount ΔHm that appears during the temperature rise process. If there are more than two endothermic peaks during the heating process, then the heat ΔHm is the sum of the two or more endothermic peaks. If ΔHm is less than 30 J/g, the crystallinity of the polyester resin decreases, and the dielectric loss tends to increase. Furthermore, ΔHm is preferably 35 J/g or more, and more preferably 40 J/g or more.

The glass transition temperature of the polyester resin in the present invention is preferably 41°C to 90°C. The glass transition temperature can be measured by the following method: using a differential scanning calorimeter in a nitrogen atmosphere, the polyester resin is rapidly cooled from a molten state, and then the temperature is raised at a temperature rise rate of 20°C/min. The measured value is The glass transition temperature that occurs during the heating process. When the glass transition temperature is less than 41°C, the mobility of the amorphous region of the polyester resin will increase, and the dielectric loss of the polyester resin will tend to increase. Furthermore, the lower limit of the glass transition temperature of the polyester resin of the present invention is preferably 42°C or higher, and more preferably 43°C or higher. On the other hand, when the glass transition temperature is higher than 90°C, the proportion of the amorphous region of the polyester resin increases, resulting in a decrease in its crystallinity, and the dielectric loss of the polyester resin tends to increase. The upper limit of the glass transition temperature is preferably 70°C or less, and more preferably 60°C or less.

The dielectric loss tangent value of the polyester resin obtained in the present invention at a frequency of 5.8 GHz measured by the cavity resonance method is preferably 0.0060 or less, more preferably 0.0055 or less, and still more preferably 0.0051 or less.

The polyester resin of the present invention can be prepared by the following method: a raw material with a molar ratio of diol component to dicarboxylic acid component of 1.05-1.50 is carried out under normal pressure or reduced pressure in the temperature range of 150 to 250°C. The esterification reaction or the transesterification reaction is followed by the condensation reaction at a temperature of 240 to 270°C and a pressure of 500 Pa or less. The molar ratio of the diol component to the dicarboxylic acid component is controlled within the above-mentioned range, and the diol component represented by Formula 1 can be efficiently polymerized into the polyester resin. Furthermore, the molar ratio of the diol component/dicarboxylic acid component is preferably 1.10 or more, and more preferably 1.15 or more. On the other hand, the above-mentioned molar ratio is preferably 1.40 or less, and more preferably 1.30 or less.

In order to obtain a polyester resin with a high degree of polymerization, the above-mentioned condensation reaction time is preferably 100 minutes or more, and more preferably 110 minutes or more. On the other hand, in order to suppress thermal decomposition of the polyester resin, it is preferably 350 minutes or less, and more preferably 300 minutes or less.

In order to effectively carry out the esterification reaction, transesterification reaction and condensation reaction, it is preferable to add a polymerization catalyst during these reactions. Specific examples of polymerization reaction catalysis include: methyl titanate, tetra-n-propyl titanate, tetra-n-butyl titanate, Tetraisopropyl titanate, tetraisobutyl titanate, tetra-tert-butyl titanate, cyclohexyl titanate, tetraphenyl titanate, tetrabenzyl titanate, tetramethylphenyl titanate, or these titanium Organic titanium compounds such as mixtures of acid esters, dibutyl tin oxide, methyl phenyl tin oxide, tetraethyl tin oxide, hexaethyl tin oxide, cyclohexyl tin oxide, didodecyl tin oxide, Triethyl tin hydroxide, triphenyl tin hydroxide, triisobutyl tin acetate, dibutyl tin diacetate, diphenyl tin dilaurate, butyl tin trichloride, dibutyl tin dichloride, tributyl Tin chloride, dibutyltin sulfide, butyl oxyhydroxide, alkyl stannic acid (such as methyl stannic acid, ethyl stannic acid, butyl stannic acid, etc.) and other tin compounds, zirconium compounds such as n-butoxide, trioxide Antimony, antimony acetate and other antimony compounds. From the viewpoints of promoting the polymerization reaction rate and suppressing thermal degradation and side reactions during the reaction, organic titanium compounds and tin compounds are more preferred, and tetra-n-propyl titanate, tetra-n-butyl titanate, and titanium are more preferred. Tetraisopropyl titanate is most preferably tetra-n-butyl titanate. The above-mentioned polymerization catalysts may be added singly or two or more of them may be added in combination. According to mechanical properties, formability and color requirements, the amount of the polymerization catalyst added is preferably 0.005 to 0.5 parts by weight, and more preferably 0.01 to 0.2 parts by weight relative to 100 parts by weight of the polyester resin.

In addition, the present invention also relates to a polyester resin composition containing the polyester resin. In addition, the polyester resin composition may further include a filler. The filling material can include but is not limited to the following examples: glass fiber, carbon fiber, potassium titanate whisker, zinc oxide whisker, aluminum borate whisker, alumina fiber, silicon carbide fiber, ceramic fiber, asbestos fiber, gypsum fiber Or fibrous inorganic or organic fillers such as metal fibers; wollastonite, zeolite, sericite, kaolin, mica, talc, clay, pyrophyllite, bentonite, montmorillonite, asbestos, silicate, alumina, silica , Magnesium Oxide, Zirconium Oxide, Titanium Oxide, Iron Oxide, Calcium Carbonate, Magnesium Carbonate, Dolomite, Calcium Sulfate, Barium Sulfate, Magnesium Hydroxide, Calcium Hydroxide, Aluminum Hydroxide, Glass Beads, Ceramic Beads, Nitriding Non-fibrous inorganic fillers such as boron, silicon carbide or silicon dioxide. The filling material may be hollow. In addition, the filling material may be treated with a coupling agent such as an isocyanate compound, an organosilane compound, an organic titanate compound, an organoborane compound, or an epoxy compound. The above-mentioned montmorillonite may also be an organic montmorillonite in which interlamellar ions are cation-exchanged by organic ammonium salt. From the viewpoints of improving the mechanical properties of the polyester resin composition and reducing the molding shrinkage rate, the above-mentioned filler is preferably a fibrous inorganic filler, and more preferably glass fiber or carbon fiber. The cross-sectional shape of the fibrous filler is not particularly limited, and it may be circular or flat. In addition, the above-mentioned fillers can be added alone or two or more of them can be added in combination.

The said polyester resin composition contains the above-mentioned filler in a mixing amount of preferably 0.1 to 150 parts by weight with respect to 100 parts by weight of the polyester resin. The lower limit of the mixing amount of the filler is more preferably 1 part by weight or more, still more preferably 10 parts by weight or more, and still more preferably 30 parts by weight or more. On the other hand, the upper limit of the mixing amount of the filler is more preferably 100 parts by weight or less, and still more preferably 80 parts by weight or less.

The polyester resin composition of the present invention may also contain additives such as stabilizers, nucleating agents, antioxidants, mold release agents, flame retardants, and color master batches.

The stabilizer can be exemplified as phosphoric acid, trimethyl phosphate, triethyl phosphate, triethyl phosphonoacetate, 3,9-bis(2,6-di-tert-butyl-4-methylphenoxy) -2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane, tetrakis(2,4-di-tert-butyl-5-methylphenyl)[1,1 -Biphenyl]-4,4'-diyl bisphosphonate and the like.

As the nucleating agent, at least one of an inorganic crystal nucleating agent or an organic crystal nucleating agent can be used. The inorganic crystal nucleating agent may be exemplified by silica, alumina, zirconia, titania, wollastonite, kaolin, talc, mica, or silicon carbide.

In addition, the organic crystal nucleating agent may, for example, be an aliphatic carboxylic acid amide, a metal carboxylic acid salt, or a sorbitol derivative. Among the aliphatic carboxylic acid amides, examples include lauric acid amide, palmitic acid amide, oleic acid amide, stearic acid amide, erucic acid amide, behenic acid amide, ricinoleic acid amide, or hydroxystearic acid amide. And other aliphatic monocarboxylic acid amides, N-oleyl palmitic acid amide, N-oleyl oleic acid amide, N-oleyl stearic acid amide, N-stearyl oleic acid amide, N-stearic acid amide Fatty stearic acid amide, N-stearyl erucic acid amide, N-hydroxymethyl stearic acid amide, or N-hydroxymethyl behenic acid amide and other N-substituted aliphatic monocarboxylic acid amides, sub Methyl bis stearic acid amide, ethylene bis lauric acid amide, ethylene bis capric acid amide, ethylene bis oleic acid amide, ethylene bis stearic acid amide, ethylene bis erucic acid amide, ethylene Bisbehenic acid amide, ethylene bisisostearic acid amide, ethylene bishydroxystearic acid amide, butylene bisstearic acid amide, hexamethylene bisoleic acid amide, hexamethylene bisstearic acid amide Fatty acid amide, hexamethylene bisbehenic acid amide, hexamethylene bishydroxystearic acid amide, m-xylylene bis-stearic acid amide, or m-xylylene bis-12-hydroxystearic acid Aliphatic biscarboxylic acid amides such as amides, N,N'-dioleyl sebacic acid amide, N,N'-dioleyl adipamide, N,N-distearyl adipate N-amide, N,N'-distearyl sebacamide, N,N'-distearyl isophthalic acid amide, or N,N'-distearyl terephthalic acid amide, etc. Substituted aliphatic carboxylic acid diamides, N-butyl-N'-stearyl urea, N-propyl-N'-stearyl urea, N-stearyl-N'-stearyl urea, N -Phenyl-N'-stearyl urea, xylylene bisstearyl urea, tolyl bisstearyl urea, hexamethylene bisstearyl urea, diphenylmethane bisstearyl urea, or N-substituted ureas such as diphenylmethane dilauryl urea.

Examples of the carboxylic acid metal salt include sodium benzoate, potassium benzoate, lithium benzoate, calcium benzoate, magnesium benzoate, barium benzoate, lithium terephthalate, sodium terephthalate, terephthalate Potassium formate, calcium oxalate, sodium laurate, potassium laurate, sodium myristate, potassium myristate, calcium myristate, sodium octadecyl, calcium octadecyl, sodium stearate, Potassium stearate, lithium stearate, calcium stearate, magnesium stearate, barium stearate, sodium montanate, calcium montanate, sodium toluate, sodium salicylate, potassium salicylate, salicylic acid Zinc, aluminum dibenzoate, potassium dibenzoate, lithium dibenzoate, sodium naphthalate, sodium cyclohexanoate.

Examples of the sorbitol derivatives include bis(p-methylbenzylidene)sorbitol, bis(p-methylbenzylidene)sorbitol, bis(p-ethylbenzylidene)sorbitol, and bis(p-methylbenzylidene)sorbitol. Chlorobenzylidene) sorbitol, bis(p-bromobenzylidene) sorbitol, or sorbitol derivatives obtained by chemical modification of the above-mentioned sorbitol derivatives, etc.

Considering the effect of promoting the crystallization of the polyester resin, the nucleating agent is preferably silica, wollastonite, kaolin, talc, mica, or aliphatic carboxylic acid amide. In addition, in the polyester resin composition of the present invention, the content of the nucleating agent is preferably 0.05 to 5 parts by weight relative to 100 parts by weight of the polyester resin. Within this range, the crystallization promotion effect can be maintained, and a polyester resin composition having excellent toughness can be obtained. Further, the lower limit of the content of the nucleating agent is more preferably 0.1 parts by weight or more. In addition, the upper limit thereof is more preferably 3 parts by weight or less, and still more preferably 2 parts by weight or less.

The antioxidant is preferably at least one of a phenol-based antioxidant or a sulfur-based antioxidant. In order to obtain better heat resistance and thermal stability, it is preferable to use a phenol-based antioxidant and a sulfur-based antioxidant in combination.

Among the phenolic antioxidants, for example, 2,4-dimethyl-6-tert-butylphenol, 2,6-di-tert-butylphenol, 2,6-di-tert-butyl-p-cresol, 2,6-Di-tert-butyl-4-ethylphenol, 4,4'-butylene bis(6-tert-butyl-3-methylphenol), 2,2'-methylene bis(4-methyl 6-tert-butylphenol), 2,2'-methylene-bis(4-ethyl-6-tert-butylphenol), octadecyl-3-(3',5'-di-tert Butyl-4'-hydroxybenzene) propionate, pentaerythritol tetra[3-(3,5-di-tert-butyl-4-hydroxybenzene)]propionate], 1,1,3-tris(2-methyl 4-hydroxy-5-di-tert-butylphenyl)butane, tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanurate, triethylene glycol-bis[3-(3 -Tert-butyl-4-hydroxy-5-methylbenzene)propionate], 1,6-hexanediol bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate ], 2,4-bis(n-octylthio)-6-(4-hydroxy-3,5-di-tert-butylanilino)-1,3,5-triazine, 2,2-thiobis Ethylene bis[3-(3,5-di-tert-butyl-4-hydroxybenzene) propionate], N,N'-hexamethylene bis(3,5-di-tert-butyl-4-hydroxyhydrocinnamon) Amide), 3,5-di-tert-butyl-4-hydroxybenzylphosphonate diethyl, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl- 4-hydroxybenzyl)benzene, tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanurate, 2,4-bis[(octylthio)methyl]o-cresol, or Isooctyl-3-(3,5-di-tert-butyl-4-hydroxybenzene) propionate and the like.

The sulfur-based antioxidants include dilauryl thiodipropionate, dimyristyl thiodipropionate, distearyl thiodipropionate, di(tridecyl)sulfur Dipropionate, pentaerythryl (3-lauryl thiopropionate), or 2-mercaptobenzimidazole, etc.

The above-mentioned antioxidants can be used alone, and at the same time, since the combination of two or more antioxidants will produce an additive or synergistic effect, they can also be used in combination.

In the polyester resin composition of the present invention, relative to 100 parts by weight of the polyester resin, the content of the antioxidant is preferably 0.01 to 3 parts by weight. Within this range, the anti-oxidation effect can be maintained while suppressing the generation of gas during melt processing. Furthermore, the lower limit of the antioxidant content is more preferably 0.05 parts by weight or more, and even more preferably 0.1 parts by weight or more. In addition, the upper limit thereof is more preferably 2 parts by weight or less, and still more preferably 1 part by weight or less.

The mold release agent is not particularly limited, and any mold release agent used for general thermoplastic resins can be used. Specifically, fatty acids, fatty acid metal salts, hydroxy fatty acids, fatty acid esters, aliphatic partially saponified esters, paraffins, low molecular weight polyolefins, fatty acid amides, alkylene bis fatty acid amides, aliphatic ketones, fatty acid lower Alcohol ester, fatty acid polyol ester, fatty acid polyglycol ester, or modified polysiloxane, etc.

The fatty acid is preferably a fatty acid having 6 to 40 carbon atoms, specifically oleic acid, lauric acid, stearic acid, hydroxystearic acid, behenic acid, arachidonic acid, linoleic acid , Linolenic acid, ricinoleic acid, palmitic acid, stearic acid, montanic acid, or their mixtures.

The fatty acid metal salt is preferably a fatty acid alkali metal salt or alkaline earth metal salt having 6 to 40 carbon atoms, and specifically, calcium stearate, sodium montanate, or calcium montanate can be exemplified.

The hydroxy fatty acid can be exemplified by 1,2-hydroxy fatty acid and the like.

The fatty acid ester can be exemplified as stearate, oleate, linoleate, linoleate, adipate, behenate, arachidonic acid, montanate, Isostearate, or ester of polymeric acid, etc.

The aliphatic partially saponified ester may be exemplified by montanic acid partially saponified ester.

The paraffin is preferably a paraffin having 18 or more carbon atoms, and can be exemplified by liquid paraffin, natural paraffin, microcrystalline wax, or petrolatum.

The low-molecular-weight polyolefin is preferably a polyolefin with a weight average molecular weight of 5000 or less, specifically, polyethylene wax, maleic acid-modified polyethylene wax, oxidized polyethylene wax, chlorinated polyethylene wax, Or polypropylene wax and so on.

The fatty acid amide is preferably a fatty acid amide having 6 or more carbon atoms, and specifically, oleic acid amide, erucic acid amide, or behenic acid amide can be exemplified.

The alkylene bis fatty acid amide is preferably an alkylene bis fatty acid amide having 6 or more carbon atoms, specifically, methylene bis stearamide, ethylene bis stearamide, or N, N -Bis (2-hydroxyethyl) stearamide and the like.

The aliphatic ketone can be exemplified by higher aliphatic ketones and the like.

The fatty acid lower alcohol ester is preferably a fatty acid lower alcohol ester having 6 or more carbon atoms, specifically, ethyl stearate, butyl stearate, ethyl behenate, or rice wax, etc. .

The fatty acid polyol ester may be exemplified as glycerol monostearate, pentaerythritol monostearate, pentaerythritol tetrastearate, pentaerythritol adipate stearate, and dipentaerythritol adipate stearate , Or sorbitan monostearate and so on.

The fatty acid polyglycol ester may be exemplified as polyethylene glycol fatty acid ester or polypropylene glycol fatty acid ester.

The modified polysiloxane may be exemplified by methyl styryl modified polysiloxane, polyether modified polysiloxane, higher fatty acid alkoxy modified polysiloxane, and higher fatty acid-containing Polysiloxane, higher fatty acid ester modified polysiloxane, methacrylic acid modified polysiloxane, or fluorine modified polysiloxane, etc.

The flame retardant may be exemplified as a bromine-based flame retardant, including decabromodiphenyl ether, octabromodiphenyl ether, tetrabromodiphenyl ether, tetrabromophthalic anhydride, hexabromocyclododecane Alkyl, bis(2,4,6-tribromophenoxy)ethane, ethylenebistetrabromophthalimide, hexabromobenzene, 1,1-sulfonyl [3,5-dibromo -4-(2,3-dibromopropoxy)]benzene, polydibromophenylene oxide, tetrabromobisphenol-S, tris(2,3-dibromopropyl) isocyanurate, Tribromophenol, tribromophenyl allyl ether, tribromoneopentyl alcohol, brominated polystyrene, brominated polyethylene, tetrabromobisphenol-A, tetrabromobisphenol-A derivatives, brominated ring Oxygen resins such as tetrabromobisphenol-A-epoxide oligomers or polymers and brominated phenol novolac epoxides, tetrabromobisphenol-A-carbonate oligomers or polymers, tetrabromobis Phenol-A-bis(2-hydroxydiethyl ether), tetrabromobisphenol-A-bis(2,3-dibromopropyl ether), tetrabromobisphenol-A-bis(allyl ether), Tetrabromocyclooctane, ethylene bis-pentabromodiphenyl, tris(tribromoneopentyl) phosphate, poly(pentabromobenzyl polyacrylate), octabromotrimethylphenylindane, two Bromoneopentyl glycol, pentabromobenzyl polyacrylate, dibromotolyl glycidyl ether, or N,N'-ethylene-bis-tetrabromoterephthalimide, etc. In the present invention, the aforementioned flame retardant may also be exemplified as a chlorine-based flame retardant, including chlorinated paraffin, chlorinated polyethylene, perchlorocyclopentadecane, or tetrachlorophthalic anhydride, and the like.

The polyester resin of the present invention or the composition containing the polyester resin of the present invention can be molded into a compound having an arbitrary molding method such as injection molding, extrusion molding, blow molding, vacuum molding, melt spinning, or film molding. Molded products of the desired shape.

The molded article of the present invention can be used as mechanical structural parts, electrical parts, electronic parts, automobile parts, etc., due to its good mechanical properties and heat resistance. Since the molded article of the present invention has excellent dielectric properties at high frequencies, it can be used particularly as a high-frequency communication transmission part.

Specific examples of mechanical structural parts, electrical parts, electronic parts, and automotive parts include: circuit breakers, electromagnetic switches, focus boxes, flyback transformers, fuser parts such as copies and printers, general household electrical products, OA machines, etc. Housing protection parts, variable capacitors, various terminal boards, converters, printed circuit boards, housing protection parts, terminal blocks, coil bobbins, connectors, relays, disk drive brackets, transformers, switch parts, socket parts, motor parts , Sockets, plugs, condensers, various housings, resistors, metal terminals and wire combinations of electrical and electronic parts, computer-related parts, audio parts and other sound parts, lighting parts, telecommunication equipment-related parts, telephone equipment-related parts , Air-conditioning parts, VTR, TV and other home appliances parts, copier parts, fax parts, optical instrument parts, automobile ignition parts, automobile connectors, and various automobile electrical components.

High-frequency communication transmission components can include: 5G communication industry, wireless communication industry, satellite communication, base station, navigation, medical treatment, transportation, warehouse and other various resin parts, in mobile communication terminal, communication base station, millimeter wave sensor, vehicle Electrical and electronic components used in communication equipment, such as printed circuit boards, antenna base materials, connectors, frames, antenna housings, sensor housings, power amplifiers, power supply components, and high-frequency filters.

Detailed ways

Hereinafter, the present invention will be described in detail through examples, but the present invention is not limited thereto.

The various characteristics of the polyester resins obtained in the Examples and Comparative Examples were measured according to the following methods.

(1) Determination of the content of monomer units derived from the diol component

The polyester resin used in each example or comparative example was dissolved in deuterated HFIP (hexafluoroisopropanol) at a concentration of 30 mg/ml, and JEOL ECX 400P was used under the condition of 256 scans. Carry out ¹ H-NMR nuclear magnetic test. In the ¹ _{H-NMR spectrum, the peaks corresponding to the hydrogen on the methylene group (-CH 2} -O-) adjacent to the oxygen in the various structures and the main component of the polyester main chain repeating unit are derived from the pair After assigning the peaks corresponding to hydrogen on the monomer unit of the phthalic acid and/or its ester-forming derivative, the peaks are integrated to obtain the peak area. The polyester resin is calculated based on the peak area corresponding to hydrogen on the monomer unit of the polyester main chain derived from terephthalic acid and/or its ester-forming derivative, and combined with the number of hydrogen atoms contained in each structure The content of various structural units.

(2) Melting point (Tm)

Using TA DSC-discover250 analysis instrument, accurately weigh about 5 mg of the polyester resin sample prepared in the embodiment or comparative example, and measure it according to the following test conditions: in a nitrogen atmosphere, the obtained polyester resin is heated at a rate of 20°C/min. Raise the temperature from 30°C to 250°C to reach a fully molten state, keep it at this temperature for 2 minutes, then decrease the temperature to 30°C at a cooling rate of 20°C/min, and keep it at this temperature for 2 minutes. Next, the temperature is raised to 250°C at a heating rate of 20°C/min. The temperature of the endothermic peak observed during this heating process was taken as the melting point of the polyester resin.

(3) Heat of endothermic peak (ΔHm)

Using the TA DSC-discover250 analytical instrument, accurately weigh about 5 mg of the polyester resin sample prepared in the embodiment or the comparative example, and perform the test according to the following conditions. In a nitrogen atmosphere, the obtained polyester resin is heated from 30°C to 250°C at a heating rate of 20°C/min to reach a fully molten state, and maintained at this temperature for 2 minutes, and then reduced to a temperature of 20°C/min. 30°C and keep it at this temperature for 2 minutes. Next, the temperature is increased to 250°C at a heating rate of 20°C/min, and the heat value ΔHm of the endothermic peak that appears during the heating process is measured.

(4) Glass transition temperature (Tg)

Using the TA DSC-discover250 analytical instrument, accurately weigh about 5 mg of the polyester resin sample prepared in the embodiment or the comparative example, and perform the test according to the following conditions. In a nitrogen atmosphere, the obtained polyester resin was heated from 20°C to 250°C at a heating rate of 20°C/min to reach a fully molten state, and kept at this temperature for 2 minutes, and then rapidly cooled from the molten state. The temperature is increased at a heating rate of 20°C/min, and the glass transition temperature during the heating process is measured.

(5) Dielectric loss tangent value (tanδ)

Test sample: Injection molding machine (TR30EHA) manufactured by Sodick Co., Ltd. is used to inject the polyester resin obtained in the examples or comparative examples at a molding temperature of 250°C and a mold temperature of 80°C to obtain 1mm*30mm*0.5 mm slender rectangular sample.

Dielectric loss tangent value test: adopt the cavity resonator CP521 manufactured by Agilent Technologies. Co., Ltd./Kanto Electronics Co., Ltd., and the dielectric loss tangent value measured at a frequency of 5.8 GHz.

The raw materials used in the examples and comparative examples are as follows:

Diacid composition:

Dimethyl terephthalate (DMT): TCI (Shanghai) Chemical Industry Development Co., Ltd.

Terephthalic acid (TPA): Mitsui Chemicals Co., Ltd.

Dimethyl 2,6-naphthalenedicarboxylate (DMN): Tishai (Shanghai) Chemical Industry Development Co., Ltd.

Glycol composition:

1,4-Butanediol (1,4-BDO): Mitsubishi Chemical Corporation

The glycol component that satisfies the condition (A) shown in Formula 1:

1,3-Butanediol (1,3-BDO): n=1, R3 is methyl; Tichiai (Shanghai) Chemical Industry Development Co., Ltd.

1,3-octanediol (1,3-ODO): n=1, R3 is n-pentyl; Tichiai (Shanghai) Chemical Industry Development Co., Ltd.

The glycol component that satisfies the condition (B) shown in Formula 1:

2,5-Hexanediol (2,5-HDO): n=2, R1 is methyl, R3 is methyl; Tichiai (Shanghai) Chemical Industry Development Co., Ltd.

2,5-Heptanediol (2,5-HPDO): n=2, R1 is methyl, R3 is ethyl; Tishai (Shanghai) Chemical Industry Development Co., Ltd.

2,3-Butanediol (2,3-BDO): n=0, R1 is methyl, R3 is methyl; Tishai (Shanghai) Chemical Industry Development Co., Ltd.

The diol component that satisfies the condition (C) shown in Formula 1:

2-Methyl-1,3-propanediol (2-M-1,3-PDO): n=1, R2 is methyl; Tishai (Shanghai) Chemical Industry Development Co., Ltd.

2,3-Dimethyl-1,4-butanediol (2,3-2M-1,4-BDO): n=2, R2 is methyl; Tishai (Shanghai) Chemical Industry Development Co., Ltd.

The diol component that satisfies the condition (D) shown in Formula 1:

1,2-Butanediol (1,2-BDO): R3 is ethyl; Tichia (Shanghai) Chemical Industry Development Co., Ltd.

Other glycol components:

Ethylene Glycol (EG): TCI (Shanghai) Chemical Industry Development Co., Ltd.

1,3-Propanediol (1,3-PDO): TCI (Shanghai) Chemical Industry Development Co., Ltd.

1,10-Decanediol (DDO): TCI (Shanghai) Chemical Industry Development Co., Ltd.

1,2-tetradecanediol (1,2-TDDO): TCI (Shanghai) Chemical Industry Development Co., Ltd.

catalyst:

Tetrabutyl titanate (TBT): TCI (Shanghai) Chemical Industry Development Co., Ltd.

Tin Butoxide (Ⅱ) Acid (MBO): Tichai (Shanghai) Chemical Industry Development Co., Ltd.

Other additives:

Antioxidant IR1010: BASF AG

Phosphoric acid: Tishai (Shanghai) Chemical Industry Development Co., Ltd.

Preparation Example 1: Preparation of TBT catalyst solution

100g of 1,4-butanediol and 11.2g of n-tetrabutyl titanate were put into a 250ml three-necked flask with a condenser, and heated at 150°C for 3 hours in a nitrogen atmosphere.

Preparation Example 2: Preparation of BDO solution of phosphoric acid

100g of 1,4-butanediol and 11.2g of phosphoric acid were added to a 250ml three-necked flask equipped with a condenser and fully blended.

Example 1

0.640mol of dimethyl terephthalate (DMT, 124.3g), 0.691mol of 1,4-butanediol (1,4-BDO, 62.3g), 0.077mol of 1,3-butanediol ( 1,3-BDO, 7.0g), 0.733ml of the TBT catalyst solution of Preparation Example 1 was added to a 250ml three-necked flask reactor equipped with a rectification tower. Blow in nitrogen and start stirring, and the temperature is raised to 150°C. After the transesterification reaction starts under normal pressure, the temperature is slowly raised, and the transesterification reaction is carried out when the final temperature reaches 220°C. Add the TBT catalyst solution of Preparation Example 1 to the obtained prepolymer (addition of TBT: 0.050wt% relative to the mass of the final polyester resin), IR1010 (addition: 0.050wt% relative to the mass of the final polyester resin) . Then, the polycondensation reaction was carried out under the conditions of a temperature of 250°C and a pressure of 300 Pa or less. When the torque of the stirrer reaches the desired value, the polycondensation reaction is stopped, and the polyester resin is spit out.

Example 2

Example 1 was repeated, except that 1,4-BDO was 0.653 mol and 1,3-BDO was 0.115 mol. The results are shown in Table 1.

Example 3

Repeat Example 1, except that 1,4-BDO is 0.653 mol, and 1,3-BDO is replaced with 0.115 mol of 1,3-ODO. The results are shown in Table 1.

Example 4

Example 1 was repeated, except that 1,4-BDO was 0.768 mol, and 1,3-BDO was replaced with 0.192 mol of 2,5-HDO. The results are shown in Table 1.

Example 5

Example 1 was repeated, except that 1,4-BDO was 0.768 mol, and 1,3-BDO was replaced with 0.192 mol of 2,5-HPDO. The results are shown in Table 1.

Example 6

Example 1 was repeated, except that 1,3-BDO was replaced with 0.077 mol of 2-M-1,3-PDO. The results are shown in Table 1.

Example 7

Repeat Example 1, except that 1,4-BDO is 0.653 mol, and 1,3-BDO is replaced with 0.115 mol of 2-M-1,3-PDO. The results are shown in Table 1.

Example 8

Example 1 was repeated, except that 1,3-BDO was replaced with 0.077 mol of 2,3-2M-1,4-DO. The results are shown in Table 1.

Example 9

Example 1 was repeated, except that 1,3-BDO was replaced with 0.077 mol of 1,2-BDO. The results are shown in Table 1.

Example 10

Example 1 was repeated, except that 1,4-BDO was 0.653 mol, and 1,3-BDO was replaced with 0.115 mol of 1,2-BDO. The results are shown in Table 1.

Example 11

Example 1 was repeated, except that 1,4-BDO was 0.614 mol, and 1,3-BDO was replaced with 0.154 mol of 1,2-BDO. The results are shown in Table 1.

Example 12

Example 1 was repeated, except that 1,4-BDO was 0.499 mol, and 1,3-BDO was replaced with 0.269 mol of 1,2-BDO. The results are shown in Table 1.

Example 13

Example 1 was repeated, except that DMT was 0.608 mol, DMN was 0.032 mol, 1,4-BDO was 0.653 mol, and 1,3-BDO was replaced with 0.115 mol of 1,2-BDO. The results are shown in Table 1.

Example 14

Example 1 was repeated, except that DMT was 0.544 mol, DMN was 0.096 mol, 1,4-BDO was 0.653 mol, and 1,3-BDO was replaced with 0.115 mol of 1,2-BDO. The results are shown in Table 1.

Example 15

Add 0.640mol of terephthalic acid (TPA, 106.2g), 0.749mol of 1,4-butanediol (1,4-BDO, 67.5g), and MBO (addition: 0.042 relative to the mass of the final polyester resin wt%) and IR1010 (addition: 0.019 wt% relative to the mass of the final polyester resin) were added to a 250ml four-neck flask reactor equipped with a rectification tower. Blow in nitrogen and start stirring. After the temperature is raised to 100°C, the TBT catalyst solution of Preparation Example 1 (addition amount: 0.045 wt% relative to the final polyester resin mass) is added, and the pressure is reduced to 66KPa for esterification reaction, and slowly Raise the temperature, after 60 minutes of reaction, when the temperature is raised to 195°C, return to normal pressure with nitrogen and slowly add 0.083 mol 1,2-butanediol (1,2-BDO, 7.5g) under a nitrogen flow of 50ml/min. And the addition is completed within 60 minutes. The esterification reaction was carried out under the condition that the final temperature reached 233°C after the reaction for 200 minutes, and the reaction was terminated when the reaction liquid became transparent. The TBT catalyst solution of Preparation Example 1 (TBT addition amount: 0.050 wt% relative to the mass of the final polyester resin) was added to the obtained prepolymer, and the phosphoric acid solution of Preparation Example 2 (phosphoric acid addition amount: relative to the final polyester resin 0.017wt% of the mass), IR1010 (addition: 0.021wt% relative to the mass of the final polyester resin). Then, the polycondensation reaction was carried out under the conditions of a temperature of 245°C and a pressure of 500 Pa or less. When the torque of the stirrer reaches the desired value, the polycondensation reaction is stopped, and the polyester resin is spit out.

Comparative example 1

Example 1 was repeated, except that 1,4-BDO was 0.768 mol and 1,3-BDO was not added. The results are shown in Table 2.

Comparative example 2

Example 1 was repeated, except that 1,4-BDO was 0.422 mol, and 1,3-BDO was replaced with 0.347 mol of 1,2-BDO. The results are shown in Table 2.

Comparative example 3

Example 1 was repeated, except that 1,3-BDO was replaced with 0.077 mol of EG. The results are shown in Table 2.

Comparative example 4

Example 1 was repeated, except that 1,3-BDO was replaced with 0.077 mol of 1,3-PDO. The results are shown in Table 2.

Comparative example 5

Example 1 was repeated, except that 1,3-BDO was replaced with 0.077 mol of DDO. The results are shown in Table 2.

Comparative example 6

Example 1 was repeated, except that 1,4-BDO was 0.653 mol, and 1,3-BDO was replaced with 0.115 mol of 1,2-TDDO. The results are shown in Table 2.

Comparative example 7

Example 1 was repeated, except that 1,4-BDO was 0.320 mol, and 1,3-BDO was replaced with 0.320 mol of 2,3-BDO. The results are shown in Table 2.

Comparative example 8

Example 1 was repeated, except that 1,4-BDO was 0.192 mol, 1,3-BDO was 0.061 mol, and 0.515 mol of 1,3-PDO was added. The results are shown in Table 2.

Comparative example 9

Example 1 was repeated, except that 1,4-BDO was 0.960 mol, and 1,3-BDO was replaced with 0.320 mol of 2-M-1,3-PDO. The results are shown in Table 2.

[Table 1]

[Table 2]

In Table 1 and Table 2, Examples 1-12 and Comparative Example 1 illustrate the dielectric loss tangent value of a polyester resin containing a specific amount of monomer units derived from a diol with a side chain shown in Formula 1. smaller. Example 1 and Comparative Example 6 illustrate that the polyester resin with a longer side chain diol unit has a larger dielectric loss tangent value. Examples 9-12, Example 15 and Comparative Example 2 illustrate that for polyester resins, when the content of the monomer unit derived from the diol represented by Formula 1 is too large, the dielectric loss tangent value cannot be reduced. Comparative Examples 3 to 5 illustrate that polyester resins containing linear diol units other than 1,4-butanediol units have relatively large dielectric loss tangent values. Examples 6 and 7 and Comparative Example 9 show that the dielectric loss tangent value becomes significantly larger when the melting point is lower.

Claims (7)

A polyester resin prepared by polymerizing at least a dicarboxylic acid component and a diol component; wherein the dicarboxylic acid component contains terephthalic acid and/or its ester-forming derivatives, The diol component contains 1,4-butanediol and the diol represented by the following formula 1; relative to the total amount of monomer units derived from the diol component in the polyester resin, it is derived from 1,4 -The content of monomer units of butanediol is 70-98 mol%, and the content of monomer units derived from the diol shown in the following formula 1 is 2-30 mol%; the melting point Tm of the polyester resin is 185°C or higher , 【Formula 1】

The formula 1 satisfies any one of the following conditions (A)-(D), (A), n is an integer of 1 to 4, R1 and R2 are hydrogen elements, and R3 is an aliphatic hydrocarbon group with 1 to 6 carbon atoms; (B), n is an integer from 0 to 4, R2 is a hydrogen element, and R1 and R3 are independently an aliphatic hydrocarbon group with 1 to 6 carbon atoms; (C), n is an integer from 1 to 4, R1 and R3 are hydrogen elements, R2 is independently a hydrogen element or an aliphatic hydrocarbon group with 1 to 6 carbon atoms, wherein at least one of R2 is a carbon atom number 1. ～6 aliphatic hydrocarbon group; (D), n is 0, R1 is a hydrogen element, and R3 is an aliphatic hydrocarbon group with 2-8 carbon atoms. The polyester resin according to claim 1, wherein the total amount of monomer units derived from the dicarboxylic acid component in the polyester resin is derived from terephthalic acid and/or can form The monomer unit content of the ester derivative is 80-100 mol%. The polyester resin according to claim 1, wherein the polyester resin is reduced from a molten state to 30°C at a temperature drop rate of 20°C/min using a differential scanning calorimeter in a nitrogen atmosphere, and then The heat amount ΔHm of the endothermic peak that appears during the temperature increase process measured at the temperature increase rate of 20°C/min is 30 J/g or more. The polyester resin according to claim 1, wherein the dielectric loss tangent value of the polyester resin at a frequency of 5.8 GHz measured by the cavity resonance method is 0.0060 or less. A method for preparing the polyester resin according to any one of claims 1 to 4, characterized in that it comprises the following steps: the molar ratio of the diol component/dicarboxylic acid component is 1.05-1.50 to 150 In the temperature range of ~250°C, the esterification reaction or the transesterification reaction is carried out under normal pressure or reduced pressure, and then the condensation reaction is carried out at a temperature of 240 to 270°C and under a pressure of 500 Pa or less. A polyester resin composition characterized by containing a filler in a mixing amount of 0.1 to 150 parts by weight relative to 100 parts by weight of the polyester resin according to any one of claims 1 to 4. A molded article characterized by being produced from the polyester resin according to any one of claims 1 to 4 or the polyester resin composition according to claim 6.