JP2012122023A - Liquid crystalline polyester - Google Patents

Abstract

[Problem] To provide a polyester copolymerized with a plant-derived monomer and excellent in heat resistance and flame retardancy.
A dicarboxylic acid component (A), a glycol component (B), and an aromatic hydroxycarboxylic acid component (C), and the total amount of (A), (B), and (C) is 100 mol%, A liquid crystal polyester having a copolymerization amount of (C) of 40 to 90 mol% and a copolymerization amount of 2,5-furandicarboxylic acid of 5 to 30 mol% and a glycol component (B) are glycols containing a phosphorus atom. Liquid crystalline polyester.
[Selection figure] None

Description

  The present invention relates to a liquid crystal polyester using 2,5-furandicarboxylic acid and excellent in flame retardancy.

  From the viewpoint of environmental conservation, bioplastics using plant-derived monomers such as furandicarboxylic acid have attracted attention. Polyester resins using flanged carboxylic acid are superior in heat resistance to polylactic acid, which is a representative of bioplastics, and are expected to be applied in various fields (Patent Documents 1 to 4).

JP 2007-146153 A JP 2009-62465 A JP 2009-263509 A JP 2008-291243 A

  In recent years, from the viewpoint of safety, bioplastics are also required to have improved flame retardancy, and bioplastics that are good in both heat resistance and flame retardancy are expected.

  However, the polyester resins of Patent Documents 1 to 4 have a problem of low flame retardancy and easy combustion.

  As a result of intensive studies to solve such problems, the present inventors have been able to develop liquid crystallinity by copolymerizing a specific amount of aromatic hydroxycarboxylic acid with polyester using 2,5-furandicarboxylic acid. Thus, the present inventors have found that heat resistance and flame retardancy are improved, and have reached the present invention. That is, the gist of the present invention is as follows.

(1) It consists of a dicarboxylic acid component (A), a glycol component (B), and an aromatic hydroxycarboxylic acid component (C), and (A), (B), and (C) in a total of 100 mol%, A liquid crystal polyester having a copolymerization amount of C) of 40 to 90 mol% and a copolymerization amount of 2,5-furandicarboxylic acid of 5 to 30 mol%.
(2) The liquid crystalline polyester according to (1), wherein the glycol component (B) is a phosphorus atom-containing glycol.
(3) The liquid crystalline polyester according to (1) or (2), which contains an aromatic dicarboxylic acid as the dicarboxylic acid component (A).

  ADVANTAGE OF THE INVENTION According to this invention, the plant origin monomer can be copolymerized and the polyester excellent in heat resistance and a flame retardance can be provided.

  Hereinafter, the present invention will be described in detail.

  The liquid crystal polyester is composed mainly of a dicarboxylic acid component (A), a glycol component (B), and an aromatic hydroxycarboxylic acid component (C).

  As the dicarboxylic acid component (A), it is necessary to copolymerize 2,5-furandicarboxylic acid. 2,5-furandicarboxylic acid can be obtained by hydrolyzing the ester derivative. The ester derivative can be synthesized from, for example, galactaric acid obtained by oxidizing galactose with nitric acid (Japanese Patent Laid-Open No. 2008-127282), or can be synthesized from a monosaccharide such as fructose (Topics in Catalysis, 13, p237-242, 2000).

  The copolymerization amount of 2,5-furandicarboxylic acid is required to be 5 to 30 mol% with respect to the total of 100 mol% of (A), (B) and (C), and 10 to 25 mol%. It is preferable to set it as 15-20 mol%. If the copolymerization amount of 2,5-furandicarboxylic acid is less than 5 mol%, the proportion of the plant-derived monomer is decreased, and the environmental merit is reduced, which is not preferable. On the other hand, when the copolymerization amount of 2,5-furandicarboxylic acid exceeds 90 mol%, liquid crystal properties are not exhibited and flame retardancy is lowered, which is not preferable.

  Examples of other dicarboxylic acids constituting the dicarboxylic acid component include aromatic dicarboxylic acids, alicyclic dicarboxylic acids, and aliphatic dicarboxylic acids. Of these, aromatic dicarboxylic acids are preferable because liquid crystallinity is easily exhibited and flame retardancy is improved.

  Aromatic dicarboxylic acids include terephthalic acid, isophthalic acid, 4,4′-diphenyldicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 1,6-naphthalenedicarboxylic acid, diphenyl ether-4,4′-dicarboxylic acid, diphenoxy Ethane-4,4′-dicarboxylic acid, diphenoxybutane-4,4′-dicarboxylic acid, diphenylethane-4,4′-dicarboxylic acid, diphenyl ether-3,3′-dicarboxylic acid, diphenoxy ether-3,3 Examples include '-dicarboxylic acid and diphenylethane-3,3'-dicarboxylic acid. Among these, terephthalic acid, isophthalic acid, 4,4'-diphenyldicarboxylic acid, and 2,6-naphthalenedicarboxylic acid are preferable.

  Examples of the alicyclic dicarboxylic acid include 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 2,5-norbornene dicarboxylic acid, and the like.

  Aliphatic dicarboxylic acids include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, hydrogenated dimer acid, fumaric acid, maleic acid, itacone An acid, a citraconic acid, a dimer acid, etc. are mentioned.

  Examples of the glycol component (B) include aromatic glycols and aliphatic glycols. Among these, aromatic glycol is preferable because it easily exhibits liquid crystallinity.

  Aromatic glycols include hydroquinone, resorcin, 4,4′-dihydroxydiphenyl, 2,6-naphthalenediol, 4,4′-dihydroxydiphenyl ether, bis (4-hydroxyphenoxy) ethane, 3,3′-dihydroxydiphenyl, 3,3′-dihydroxydiphenyl ether, 1,6-naphthalenediol, 2,2-bis (4-hydroxyphenyl) propane, 2,2-bis (4-hydroxyphenyl) methane, methylhydroquinone, t-butylhydroquinone, phenyl Hydroquinone, phenoxyhydroquinone, 4-methylresorcin, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide represented by chemical formula (1) and a reaction product of hydroquinone (HCA-HQ), dipheny Phosphylhydroquinone (PPQ), ethylene glycol adduct of diphenylphosphil hydroquinone (PPQ-E), 1,4-cyclooctylphosphonyl-1,4-benzenediol and / or 1,5-cyclooctylphosphonyl-1 , 4-benzenediol (CHPO-HQ), 2-carboxyethylphenylphosphinic acid (CEPPA), and the like. Among these, HCA-HQ, PPQ, PPQ-E, CHPO-HQ, and CEPPA containing a phosphorus atom are more preferable because flame retardancy is improved.

  Examples of the aliphatic glycol include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2-methyl-1, 3-propanediol, 2,2-diethyl-1,3-propanediol, 2-amino-2-ethyl-1,3-propanediol, 2-amino-2-methyl-1,3-propanediol, 2- Ethyl-2-methyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, Triethylene glycol, polypropylene glycol, and among them, there are products of vegetable origin, versatile ethylene glycol. In addition, plant-derived ethylene glycol is, for example, Greencol Taiwan Corp. Can be obtained from

  Examples of the aromatic hydroxycarboxylic acid component (C) include p-hydroxybenzoic acid, m-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid, 6-hydroxy-1-naphthoic acid, 3-methyl-4-hydroxybenzoic acid. Acid, 3-methoxy-4-hydroxybenzoic acid and the like. Among these, p-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid are preferable because liquid crystallinity is easily exhibited and flame retardancy is improved.

  The copolymerization amount of the aromatic hydroxycarboxylic acid (C) is required to be 40 to 90 mol% with respect to the total of 100 mol% of (A), (B) and (C), and 50 to 80 mol. %, And more preferably 60 to 70 mol%. When the copolymerization amount of the aromatic hydroxycarboxylic acid is less than 40 mol%, liquid crystal properties are not exhibited and flame retardancy is lowered, which is not preferable. On the other hand, when the copolymerization amount of the aromatic hydroxycarboxylic acid exceeds 90 mol%, the proportion of the plant-derived monomer is decreased, and the environmental merit is decreased, which is not preferable.

  Next, the manufacturing method of the liquid crystalline polyester of this invention is demonstrated.

  Liquid crystalline polyester can be manufactured by a well-known method combining the said monomer. For example, a method comprising an acetylation reaction, an esterification reaction and a polycondensation reaction can be mentioned.

  In the acetylation reaction, all monomer components and / or low polymers thereof and acetic anhydride are charged into a reaction can, and then purged with nitrogen. Under an inert atmosphere, hydroxyl groups of all glycol components and hydroxyl groups of hydroxycarboxylic acids and anhydrides are added. Acetic acid is reacted to obtain an acetylated product. The molar ratio of acetic anhydride to the total of hydroxyl groups of the glycol component and hydroxycarboxylic acid is preferably 1.00 to 1.20. The reaction temperature is preferably 100 to 160 ° C, more preferably 130 to 150 ° C. The reaction time is preferably 1 to 5 hours.

  In the esterification reaction, an acetylated product is reacted with a carboxylic acid of a dicarboxylic acid component and a carboxylic acid of a hydroxycarboxylic acid to obtain a low polymer. The reaction temperature is preferably 180 to 240 ° C, more preferably 200 to 220 ° C. The reaction temperature is preferably raised gradually as the reaction proceeds. The reaction time is preferably 0.5 to 5 hours, more preferably 1 to 2 hours.

  In the polycondensation reaction, the acetic acid component is distilled off from the low polymer obtained by the esterification reaction under reduced pressure until the desired molecular weight is reached. The reaction temperature is preferably 290 to 350 ° C, more preferably 320 to 340 ° C. The reaction temperature is preferably raised gradually as the reaction proceeds. The degree of vacuum is preferably 130 Pa or less, and more preferably 100 Pa or less. It is preferable that the pressure is gradually reduced over 1 to 3 hours until reaching a predetermined degree of pressure reduction from atmospheric pressure.

  In the acetylation reaction, esterification reaction and polycondensation reaction, a catalyst can be used as necessary. Catalysts include organic titanate compounds such as tetrabutyl titanate, alkali metals such as zinc acetate and magnesium acetate, acetates of alkaline earth metals, organotin compounds such as antimony trioxide, hydroxybutyltin oxide, and tin octylate. Can be mentioned. The amount of the catalyst used is preferably 1.0% by mass or less with respect to the mass of the resin produced.

  If necessary, the liquid crystal polyester may contain a reinforcing material, other thermoplastic resins, pigments, heat stabilizers, antioxidants, weathering agents, and release agents.

  Examples of the reinforcing material include a fibrous reinforcing material and a filler-based reinforcing material. Examples of the fibrous reinforcing material include glass fiber, metal fiber, potassium titanate whisker, and carbon fiber. Examples of the filler-based reinforcing material include talc, calcium carbonate, mica, glass flake, and metal flake. Among these, glass fiber is preferable because the melt viscosity of the resin composition can be stabilized and the strength, elastic modulus, and heat resistance can be improved. The diameter of the glass fiber is preferably 3 to 20 μm.

  Other thermoplastic resins include polycarbonate, polyethylene terephthalate, polybutylene terephthalate, polyarylate, polycaprolactone, nylon 6, nylon 66, nylon 46, amorphous nylon, polysulfone, polyethersulfone, polyetherketone, polyetherether. Examples include ketone, polyetherimide, polyphenylene oxide, polyphenylene sulfide, acrylonitrile / butadiene / styrene copolymer resin, polymethyl methacrylate, polypropylene, polyethylene, phenoxy resin, and synthetic rubber. It is preferable that the compounding quantity of another thermoplastic resin is 30 mass parts or less with respect to 100 mass parts of liquid crystalline polyester.

  The liquid crystalline polyester of the present invention has a thermal decomposition starting temperature of 350 ° C. or higher. Therefore, it can be suitably used for components that require heat resistance.

  Further, the liquid crystalline polyester of the present invention exhibits flame retardancy of V-2 or higher in the American UL standard subject 94 (UL94), which is a general flame retardance standard. In addition, evaluation of a flame retardance is 5VA> 5VB> V-0> V-1> V-2> HB in descending order.

  Since the liquid crystalline polyester of the present invention is excellent in flame retardancy and heat resistance, it is particularly suitable for applications such as automobiles, machines and electrical / electronic devices.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

1. Evaluation item (1) Resin composition Using a high-resolution nuclear magnetic resonance apparatus (ECA500 NMR manufactured by JEOL Ltd.), ¹ H-NMR analysis was performed to determine the resin composition from the peak intensity of each copolymer component (resolution) : 500 MHz, solvent: DMSO-d ₆ , temperature: 25 ° C.).

(2) Biogenic content The biogenic content was measured in accordance with ASTM D6868 06.

(3) Thermal decomposition start temperature Using TGA-7 manufactured by PerkinElmer, the temperature of 10 mg of the sample was increased from 30 ° C. to 10 ° C./min in a nitrogen atmosphere, and the temperature at which the weight loss rate was 5% was heated. It was set as the decomposition start temperature.

(4) Flame Retardancy Test A sample was put into a mold, and melted at 330 ° C. for 2 minutes under a pressure of 10 MPa using TABLE TYPE TEST PRESS SA-303-IS of Tester Sangyo Co., Ltd. Then, it cooled until it became normal temperature, and obtained the test piece of 127 mm x 12.7 mm x thickness 2mm.
Using the obtained specimen, a combustion test was performed based on the UL94 standard.

(5) Liquid crystallinity Using a polarizing microscope with a hot stage, the sample was heated from 300 ° C. to 10 ° C./min to flow and evaluated by whether or not the polarized light was allowed to pass under crossed Nicols. A sample that passed through polarized light was determined to have liquid crystal properties, and a sample that did not pass polarized light was determined to have no liquid crystal properties. As the hot stage, a heating device for a microscope of Linking, heating-Freezing AGE TH-600 type microscope was used.

2. Raw material 2,5-furandicarboxylic acid 50 g of galactaric acid, 500 mL of 1-butanol and 100 g of sulfuric acid were added to a reaction vessel having an internal volume of 1 L equipped with a Dean-Stark tube, and heated under reflux for 8 hours in an oil bath. The produced water was removed azeotropically. After the reaction, 300 mL of diisopropyl ether and 200 mL of distilled water were added for washing, and then 200 mL of a 1% by weight aqueous sodium hydrogen carbonate solution was added once, and 200 mL of distilled water was added for washing twice. Then, the organic layer was taken out and distilled under reduced pressure (150 ° C./1.4 mmHg) to obtain dibutyl 2,5-furandicarboxylate. The yield was 47.7 mol%.
Dibutyl 2,5-furandicarboxylate was recrystallized using methanol and then hydrolyzed to obtain 2,5-furandicarboxylic acid.

Example 1
A mixture consisting of 8.2 g of 2,5-furandicarboxylic acid, 3.3 g of hydroquinone, 138.1 g of p-hydroxybenzoic acid and 129.0 g of acetic anhydride was heated in a reaction vessel at 140 ° C. for 3 hours in a nitrogen atmosphere. The acetylation reaction was carried out by stirring (2,5-furandicarboxylic acid: hydroquinone: p-hydroxybenzoic acid: acetic anhydride = 5: 5: 90: 105 (molar ratio)). 2,5-furandicarboxylic acid was derived from plants, and the other monomers were derived from petroleum. Thereafter, while stirring, the temperature of the system was raised to 210 ° C., and further raised to 290 ° C. over 1 hour to carry out an esterification reaction. Subsequently, the pressure in the system was gradually reduced to 40 Pa after 1.5 hours, and a polycondensation reaction was performed for 6 hours under these conditions. Then, after making the inside of a system into a normal pressure using nitrogen, polyester was discharged from a reaction container with nitrogen pressure, and pellet-like polyester was obtained using a strand cutter.

Examples 2-8, Comparative Examples 1-3
A polyester was obtained in the same manner as in Example 1 except that the charged resin composition was changed as shown in Table 1.

  Table 1 shows the charged resin composition, final resin composition, and characteristic values of the polyesters obtained in Examples and Comparative Examples.

Examples 1 to 8 were liquid crystal polyesters in which plant-derived monomers were copolymerized and had high heat resistance and flame retardancy.
In Examples 7 and 8, since a phosphorus atom-containing glycol was used as a glycol component, it was a liquid crystal polyester having particularly high flame retardancy compared to other examples.
Comparative Example 1 had a low biogenic content of less than 5% because the copolymerization amount of aromatic hydroxycarboxylic acid was large.
In Comparative Examples 2 and 3, since the copolymerization amount of the aromatic hydroxycarboxylic acid was small, the liquid crystallinity was not expressed and the flame retardancy was low.

Claims (3)

It consists of a dicarboxylic acid component (A), a glycol component (B), and an aromatic hydroxycarboxylic acid component (C), and the total amount of (A), (B) and (C) is 100 mol%, A liquid crystal polyester having a copolymerization amount of 40 to 90 mol% and a copolymerization amount of 2,5-furandicarboxylic acid of 5 to 30 mol%. The liquid crystalline polyester according to claim 1, wherein the glycol component (B) is a phosphorus atom-containing glycol. The liquid crystal polyester according to claim 1 or 2, comprising an aromatic dicarboxylic acid as the dicarboxylic acid component (A).