JP5650565B2 - Flame retardant transparent copolymer polyethylene naphthalate composition - Google Patents

Description

  The present invention relates to a polyester polymer excellent in flame retardancy and transparency as well as chemical resistance and surface hardness by melt polymerization using a polyethylene naphthalate resin, and a method for producing the same.

  In recent years, research and development using plastics for home appliances such as flat-screen LCD TVs has been vigorously carried out, and in the frame material of flat-screen LCD TVs, flame retardancy and transparency of molded products, as well as chemical resistance and surface hardness Is required. Currently, polycarbonate and acrylic resins are used for TV frame materials, but polycarbonate is excellent in transparency and heat resistance, but has low chemical resistance and surface hardness, and these measures have been proposed (for example, (See Patent Documents 1 to 3.) Although acrylic resin is excellent in transparency, there is a problem that flame retardancy is low (for example, see Patent Document 4). On the other hand, it is known to improve heat resistance by blending a specific phosphorus compound when imparting flame retardancy, copolymerizing technology, or copolymerizing a specific compound (for example, Patent Document 5). ~ 7). However, no resin that satisfies all these physical properties has been developed yet.

Japanese Patent Laid-Open No. 05-009285 JP 2001-207049 A JP 2010-126594 A JP 2002-080548 A JP 2000-302851 A JP 2005-194499 A Japanese Patent Laid-Open No. 2001-240660

  An object of the present invention is to provide a novel flame retardant transparent copolymerized polyethylene naphthalate composition having excellent flame retardancy and transparency, as well as chemical resistance and surface hardness.

  As a result of intensive studies to solve the above problems, the present inventors have found that a polyester resin obtained by copolymerizing a flame retardant having a specific structure and a diol is excellent in flame retardancy, transparency, chemical resistance and surface hardness. The present invention has been solved. That is, the present invention provides a polyethylene naphthalate composition obtained by copolymerizing a phosphorus compound represented by the following formula (I), wherein the intrinsic viscosity of the copolymerized polyethylene naphthalate is 0.50 dL / g or more, and the copolymerized polyethylene naphthalate. The phosphorus atom content in the phthalate composition is 10,000 to 13000 ppm, and further contains a phosphorus compound represented by the following formula (II) in an amount of 10 to 200 mmol% with respect to the divalent carboxylic acid constituting the copolymer polyethylene naphthalate. A copolymerized polyethylene naphthalate composition.

［上記式中、Ｒ^５、Ｒ^６及びＲ^７は、同一又は異なって炭素原子数１〜４のアルキル基を示し、Ｘは、−ＣＨ_２−又は―ＣＨ（Ｙ）を示す（Ｙは、ベンゼン環を示す）。］

[Wherein, R ⁵ , R ⁶ and R ⁷ are the same or different and each represents an alkyl group having 1 to 4 carbon atoms, X represents —CH ₂ — or —CH (Y) (Y represents Benzene ring). ]

  Specifically, the polyethylene naphthalate moiety is transesterified with naphthalene dicarboxylic acid and / or its ester-forming derivative, and further ethylene glycol with anhydrous calcium acetate and anhydrous magnesium acetate, then triethyl phosphonoacetate and the following formula: A copolymerized polyethylene naphthalate composition obtained by adding a phosphorus-containing element compound represented by (I) and then performing polycondensation using a titanium compound is preferred.

  The copolymerized polyethylene naphthalate composition in the present invention is characterized in that the copolymerized polyethylene naphthalate resin molded article has good flame retardancy, transparency, chemical resistance and surface hardness. Things can be provided.

The dicarboxylic acid component used in the present invention is mainly composed of 2,6-naphthalenedicarboxylic acid and 2,7-naphthalenedicarboxylic acid, but other 1,4-naphthalenedicarboxylic acid and 1,5-naphthalenedicarboxylic acid. May be copolymerized. When these naphthalene dicarboxylic acids are used as raw materials, ester-forming derivatives of these naphthalene dicarboxylic acids may be used. Furthermore, other dicarboxylic acids other than naphthalenedicarboxylic acid can be used in combination as long as the properties of the copolyester of the present invention are not impaired. For example, terephthalic acid, isophthalic acid, 4,4′-diphenyldicarboxylic acid, diphenoxyethane-4,4′-dicarboxylic acid, diphenylsulfone-4,4′-dicarboxylic acid, diphenylether-4,4′-dicarboxylic acid, etc. Examples include aromatic dicarboxylic acids, adipic acid, sebacic acid, succinic acid, oxalic acid and other aliphatic dicarboxylic acids, cyclohexanedicarboxylic acid and other alicyclic dicarboxylic acids, and one or more of these may be used. Well, you can choose arbitrarily according to the purpose. The range that does not impair the properties of the copolyester of the present invention is 30 mol% or less, preferably 20 mol% or less, based on the total dicarboxylic acid component.

The ester-forming derivative of dicarboxylic acid used in the present invention is mainly composed of dimethyl 2,6-naphthalenedicarboxylate, 2,7-naphthalenedicarboxylic dimethyl ester, diethyl ester, dipropyl ester, dibutyl ester, and diphenyl ester. . However, other dicarboxylic acid ester-forming derivatives can be used in combination as long as the properties of the copolymerized polyester of the present invention are not impaired. For example, terephthalic acid, isophthalic acid, 4,4′-diphenyldicarboxylic acid, diphenoxyethane-4,4′-dicarboxylic acid, diphenylsulfone-4,4′-dicarboxylic acid, diphenylether-4,4′-dicarboxylic acid, etc. lower alkyl esters of the aromatic dicarboxylic acids, lower alkyl esters of alicyclic dicarboxylic acids such as cyclohexane dicarboxylic acid, adipic acid, sebacic acid, succinic acid, lower alkyl esters of aliphatic dicarboxylic acids such as oxalic acid. One or more of these may be used and can be arbitrarily selected according to the purpose. As described above, the lower alkyl ester represents dimethyl ester, diethyl ester, dipropyl ester, dibutyl ester, or diphenyl ester. The range that does not impair the properties of the copolymerized polyethylene naphthalate of the present invention is 30 mol% or less, preferably 20 mol% or less, based on the ester-forming derivative component of all dicarboxylic acids.

  As the lower alkyl ester of dicarboxylic acid used in the present invention, methyl ester is the main component, but one or two of ethyl ester, propyl ester, butyl ester, etc., as long as the properties of the copolymer polyester of the present invention are not impaired. The above may be used and can be arbitrarily selected according to the purpose. The range that does not impair the properties of the copolymerized polyester of the present invention is 30 mol% or less, preferably 20 mol% or less, based on the lower alkyl ester-forming derivative component of all dicarboxylic acids. Further, a tri- or higher functional carboxylic acid component such as a small amount of trimellitic acid may be used, and a small amount of an acid anhydride such as trimellitic anhydride may be used. Further, a small amount of hydroxycarboxylic acid such as lactic acid or glycolic acid or an alkyl ester thereof may be used and can be arbitrarily selected depending on the purpose.

Furthermore, in the flame-retardant transparent copolymer polyethylene naphthalate composition of the present invention, when the total dicarboxylic acid component is 100 mol%, the aromatic dicarboxylic acid containing naphthalenedicarboxylic acid is 50 mol% or more, preferably 55 mol. % Or more, more preferably 60 mol% or more. This is because if the aromatic ring concentration is increased, the flame retardancy effect is further improved and the blocking resistance is also improved. This is because polyethylene naphthalate is an aromatic condensation resin, especially an oxygen-containing condensation resin, so it itself has the ability to form a carbonized film, expresses self-digestibility, and further a phosphorus-containing compound is copolymerized. Therefore, it is considered that this becomes phosphoric acid and polyphosphoric acid in the solid phase at the time of combustion, and promotes carbonized film formation by acting as a dehydrating agent. Moreover, by using an aromatic dicarboxylic acid, hydrolysis resistance is improved, stability at high temperature and high humidity is improved, elastic modulus at high temperature is increased, and blocking resistance is improved.

  In the present invention, ethylene glycol is used as a diol component other than these. Furthermore, ethylene glycol and phosphorus-containing phosphorus represented by the above formula (I) as a diol component constituting the polyester polymer of the present invention within a range not impairing the properties of the flame-retardant transparent copolymer polyethylene naphthalate composition of the present invention. Other diol components can be used in combination with the elemental compound. Examples of such a diol component include diols used as raw materials for general polyesters such as 1,2-propylene glycol, trimethylene glycol (1,3-propanediol), 1,4-butanediol, , 5-pentanediol, 1,6-hexanediol, 1,9-nonanediol, decamethylene glycol, neopentyl glycol, 2-methyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2 -Linear or branched aliphatic diols such as methyloctanediol; 1,4-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,2-cyclohexanedimethanol, 1,1-cyclohexanedimethanol, 2 -Methyl-1,1-cyclohexanediol, hydrogenated bisphenol A, 2,2-norbornanedimethanol, 3-methyl-2,2-norbornanedimethanol, 2,3-norbornanedimethanol, 2,5-norbornanedimethanol, 2,6-norbornanedimethanol, perhydro-1 , 4: 5,8-dimethanonaphthalene-2,3-dimethanol, adamantane dimethanol, 1,3-dimethyl-5,7-adamantane dimethanol, 1,3-adamantanediol, 1,3-dimethyl-5 , 7-adamantanediol, and the like; hydroquinone, catechol, resorcin, naphthalene diol, xylylene diol, bisphenol A, bisphenol A ethylene oxide adduct (bis-2,2- [4-β-hydroxyethoxyphenyl] Propane), bisphenol S, bisphenol Aromatic diols such as ethylene oxide adduct (bis [4-β-hydroxyethoxyphenyl] sulfone) or propylene oxide adducts of disulfur; diethylene glycol, triethylene glycol, polyethylene glycol, polytetramethylene glycol, polymethylene glycol, dipropylene And ether glycols such as glycol. The said diol component can be used arbitrarily according to the objective by mixing 1 type, or 2 or more types. Furthermore, a small amount of a polyhydric alcohol component such as glycerin may be used. A small amount of an epoxy compound may be used. The range that does not impair the properties of the flame-retardant transparent polyester of the present invention is 30 mol% or less, preferably 20 mol% or less, based on the total diol component.

The total amount of the diol component needs to be 1.5 to 2.0 mol times relative to the naphthalene dicarboxylic acid or the ester-forming derivative of naphthalene dicarboxylic acid. When the amount of the glycol component used is less than 1.5 mol times, the esterification or transesterification reaction does not proceed sufficiently, which is not preferable. Further, 2.0 if it exceeds mole times also why clear though not slower reaction rate, by-products from an excess of glycol component (e.g., diethylene glycol) a large amount of undesirably.

  Examples of the compound used as the transesterification catalyst component in the present invention include calcium, manganese, zinc, magnesium, and titanium compounds, and a combination of calcium and magnesium is most preferable. The addition amount of the calcium compound is preferably 40 ppm or less as the calcium content in the produced flame-retardant transparent polyethylene naphthalate resin. Moreover, it is preferable that the addition amount of a magnesium compound is 50 ppm or less as magnesium content in the production | generation flame-retardant transparent polyester resin.

  Various metal compounds are used as the polymerization catalyst. Antimony (Sb) compounds such as antimony trioxide are widely used for polyesters such as polyethylene naphthalate because they are inexpensive and have high polymerization activity. However, a part of the Sb compound is reduced during the reaction to produce metal Sb and other foreign substances. As a result, the color of the polymer is darkened or the manufacturing process is destabilized. There is a problem of deteriorating quality.

  As polymerization catalysts other than antimony compounds, germanium (Ge) compounds and titanium (Ti) compounds such as tetra-n-butoxy titanium have been proposed. Since the Ge compound is expensive, there is a problem that the production cost of the polyester is increased. On the other hand, when a Ti compound is used as a polymerization catalyst, the generation of the metal Sb and other foreign matters as described above is suppressed, and the above-mentioned problem with respect to foreign matters is improved. However, when a titanium compound is used as a polymerization catalyst, there is a problem peculiar to the Ti compound such that the polymer is colored yellow or the melt heat stability is poor. Therefore, a specific phosphorus compound was added in order to impart coloration with the Ti compound and melt heat stability (see JP 2004-175837 A). Thereby, coloring of a polymer is suppressed and melt heat stability is imparted. It is preferable that the addition amount of this stabilizer is 60 ppm or more as phosphorus content in the flame-retardant transparent polyethylene naphthalate composition to produce | generate. The phosphorus compound contained in the flame retardant transparent copolymer polyethylene naphthalate composition of the present invention as this stabilizer will be described in more detail later.

  As the titanium compound used as the polymerization catalyst component in the present invention, a titanium compound represented by the following formula (III) is preferably employed.

［上記式中、Ｒ^１、Ｒ^２、Ｒ^３及びＲ^４はそれぞれ同一若しくは異なって、アルキル基又はフェニル基を示し、ｍは１〜４の整数を示し、かつｍが２、３又は４の場合、２個、３個又は４個のＲ^２及びＲ^３は、それぞれ同一であっても異なっていてもどちらでもよい。］

[Wherein R ¹ , R ² , R ³ and R ⁴ are the same or different and each represents an alkyl group or a phenyl group, m represents an integer of 1 to 4, and m represents 2, 3 or 4] In this case, 2, 3 or 4 R ² and R ³ may be the same or different from each other. ]

Here, R ^{1 to} R ⁴ are preferably an alkyl group having 1 to 6 carbon atoms or a phenyl group, and m is preferably a compound having 1 or 2. Further, the titanium compound represented by the general formula (III) is specifically preferably a tetraalkyl titanate, specifically tetraethyl titanate, tetra-n-propyl titanate, tetraisopropyl titanate, tetra-n-butyl titanate, Examples include tetra-t-butyl titanate, tetraphenyl titanate, tetracyclohexyl titanate, tetrabenzyl titanate, tetraphenoxy titanium, octaalkyl trititanate, and hexaalkyl dititanate, and these may be used as mixed titanates. Among these titanium compounds, tetra-n-propyl titanate, tetraisopropyl titanate, and tetra-n-butyl titanate are particularly preferable, and tetra-n-butyl titanate is most preferable. The addition amount of the titanium compound is preferably 60 ppm or less, more preferably 40 ppm or less as the titanium atom content in the flame retardant transparent polyethylene naphthalate composition to be produced. When the amount of titanium atoms in the flame-retardant transparent polyethylene naphthalate composition to be produced exceeds 60 ppm, the color tone, transparency, and thermal stability of the copolymerized polyethylene naphthalate composition are unfavorable.

  In the present invention, it is necessary to further copolymerize a phosphorus-containing element compound represented by the following formula (I).

  The phosphorus compound to be copolymerized used in the present invention is a phosphate ester compound represented by the following general formula (I). In order to impart flame retardancy, in the present invention, a phosphorus compound represented by the following general formula (I) is copolymerized with polyethylene naphthalate. As the phosphorus compound, dicarboxylic acid which is a component of polyester or an ester thereof is used. It is a compound that can be copolymerized with a polyester by reacting with a moldable derivative. The most preferable compound among the phosphorus compounds is a compound that can introduce a phosphorus compound at a terminal or a side chain in the polyester.

  Furthermore, the phosphorus atom content of the flame retardant transparent copolymer polyethylene naphthalate composition obtained by the present invention is required to be 10,000 ppm or more from the viewpoint of flame retardancy, and preferably 10,000 to 13,000 ppm. If the phosphorus atom content in the flame retardant transparent copolymerized polyethylene naphthalate composition is 10,000 ppm or less, the flame retardancy is inferior. If it exceeds 13000 ppm, flame retardancy is obtained, but the amount added during the reaction is Increasing the number is not preferable because the reactivity, the melting point of the polymer, and the heat resistance are inferior, the transparency and the surface hardness are lowered, and the hue and haze of the obtained molded product are deteriorated. In order to make the phosphorus atom content within this range, an excessive amount of (I) calculated from the residual ratio of the compound represented by formula (I) in the production of copolymer polyethylene naphthalate is set to It is important to use it. Thereby, this range of phosphorus atom content can be achieved. The range of the phosphorus atom content is more preferably 11000 to 13000 ppm, still more preferably 12000 to 13000 ppm.

  In the flame-retardant transparent copolymer polyethylene naphthalate composition of the present invention, a monomer having a phosphorus atom is introduced by copolymerization or modification in order to impart non-halogen flame retardancy, and a phosphorus atom is included in the molecular chain. Is essential. A general method is used as a method for introducing a phosphorus atom into these resins, and among them, a method using a diesterified product of a phosphorus-containing carboxylic acid represented by the above formula (I) as a copolymerization component, as described above. Is preferable from the viewpoint of polymerization reactivity. In addition, alkyl-bis (3-hydroxypropyl) phosphine oxide, alkyl-bis (3-hydroxycarbonylethyl) phosphine oxide, etc. (all alkyls are methyl, ethyl, propyl, butyl, etc.) are used. Is also preferable.

  As the phosphorus compound contained in the copolymerized polyethylene naphthalate composition of the present application as the stabilizer described above, a phosphorus compound represented by the following general formula (II) is preferably used.

［上記式中、Ｒ^５、Ｒ^６及びＲ^７は、同一又は異なって炭素原子数１〜４のアルキル基を示し、Ｘは、−ＣＨ_２−又は―ＣＨ（Ｙ）を示す（Ｙは、ベンゼン環を示す）。］

[Wherein, R ⁵ , R ⁶ and R ⁷ are the same or different and each represents an alkyl group having 1 to 4 carbon atoms, X represents —CH ₂ — or —CH (Y) (Y represents Benzene ring). ]

  Here, the phosphorus compound represented by the general formula (II) includes carbomethoxymethanephosphonic acid, carboethoxymethanephosphonic acid, carbopropoxymethanephosphonic acid, carboptoxymethanephosphonic acid, carbomethoxy-phosphono-phenylacetic acid. , Carboethoxy-phosphono-phenylacetic acid, carboprotooxy-phosphono-phenylacetic acid, or dimethyl ester, diethyl esters, dipropyl esters or dibutyl esters of carbobutoxy-phosphono-phenylacetic acid. More specifically, trimethylphosphonoacetate, triethylphosphonoacetate (triethylphosphonoacetate), tripropylphosphonoacetate, tributylphosphonoacetate, carboethoxy-phosphono-phenylacetic acid dimethyl ester, carboethoxy-phosphono-phenylacetic acid diethylester Is preferably selected.

The above phosphorus compound is preferably contained in an amount of 10 to 200 mmol% with respect to the divalent carboxylic acid constituting the copolymer polyethylene naphthalate. More preferably, it is 20-150 mmol%, More preferably, it is 30-100 mmol%. Further, in terms of phosphorus element, it is preferable to be in the range of 5 to 120 mmol%, preferably 10 to 100 mmol%, more preferably 20 to 80 mmol%. Since the phosphorus compound is contained in a very small amount, even a person skilled in the art will refer to the present invention as copolymer polyethylene naphthalate even if the compound is contained. If the phosphorus compound is less than the lower limit, the color tone of the polyester tends to decrease, and if it exceeds the upper limit, the polymerization reaction is difficult to proceed, which is not preferable. Since the above phosphorus compound reacts relatively slowly with a titanium compound or a titanium compound component (hereinafter abbreviated as “titanium compound etc.”) as compared with a phosphorus compound usually used as a stabilizer, When the catalyst activity duration of the titanium compound or the like during the reaction is long, as a result, the amount of the titanium compound added to the polyester can be reduced, and when a large amount of stabilizer is added to the catalyst as in the present invention Even so, the heat stability of the polyester is hardly impaired. As can be seen from the examples described later, it is considered that the inclusion of this phosphorus compound ensures melting stability at the time of molding and the like and achieves improvement in transparency (haze value).

  Further, in the range not impairing the properties of the flame retardant transparent copolymer polyethylene naphthalate composition of the present invention, for example, alkyl titanates other than tetraalkyl titanates such as octaalkyl trititanate or hexaalkyl dititanate, titanium acetate and oxalic acid Weak acid salts of titanium such as titanium, titanium oxide such as titanium oxide, dibutyltin oxide, methylphenyltin oxide, tetraethyltin, hexaethylditin oxide, cyclohexahexylditin oxide, didodecyltin oxide, triethyltin hydroxide, Triphenyltin hydroxide, triisobutyltin acetate, dibutyltin diacetate, diphenyltin dilaurate, monobutyltin trichloride, dibutyltin dichlora , Organotin compounds such as tributyltin chloride, dibutyltin sulfide, butylhydroxytin oxide, potassium chloride, potassium alum, potassium formate, tripotassium citrate, dipotassium hydrogen citrate, potassium dihydrogen citrate, potassium gluconate, succinic acid Potassium, potassium butyrate, dipotassium oxalate, potassium hydrogen oxalate, potassium stearate, potassium phthalate, potassium hydrogen phthalate, potassium metaphosphate, potassium malate, tripotassium phosphate, dipotassium hydrogen phosphate, diphosphate phosphate Potassium hydrogen, potassium nitrite, potassium benzoate, potassium hydrogen tartrate, potassium bicarbonate, potassium biphthalate, potassium bicarbonate, potassium bisulfate, potassium nitrate, potassium acetate, potassium hydroxide, potassium carbonate, charcoal Potassium sodium, potassium bicarbonate, potassium lactate, potassium potassium sulfate sulfate, sodium chloride, sodium formate, trisodium citrate, disodium hydrogen citrate, sodium dihydrogen citrate, sodium gluconate, sodium succinate, sodium butyrate, Sodium trisodium oxalate, sodium hydrogen oxalate, sodium stearate, sodium phthalate, sodium hydrogen phthalate, sodium metaphosphate, sodium malate, trisodium phosphate, disodium hydrogen phosphate, sodium dihydrogen phosphate, nitrous acid Sodium, sodium benzoate, sodium hydrogen tartrate, sodium bioxalate, sodium biphthalate, sodium bitartrate, sodium bisulfate, sodium nitrate, sodium acetate, sodium hydroxide, charcoal Sodium phosphate, sodium bicarbonate, sodium lactate, sodium sulfate, sodium hydrogen sulfate, lithium chloride, lithium formate, trilithium citrate, dilithium hydrogencitrate, lithium dihydrogencitrate, lithium gluconate, lithium succinate, lithium butyrate , Dilithium oxalate, lithium hydrogen oxalate, lithium stearate, lithium phthalate, lithium hydrogen phthalate, lithium metaphosphate, lithium malate, trilithium phosphate, dilithium hydrogen phosphate, lithium dihydrogen phosphate, Lithium nitrate, lithium benzoate, lithium hydrogen tartrate, lithium deuterate, lithium biphthalate, lithium bitartrate, lithium bisulfate, lithium nitrate, lithium acetate, lithium hydroxide, lithium carbonate, lithium hydrogen carbonate, lithium lactate, sulfuric acid Lichiu , Alkali metal salts such as lithium hydrogen sulfate, calcium chloride, calcium formate, calcium succinate, calcium butyrate, calcium oxalate, calcium stearate, calcium phosphate, calcium nitrate, calcium acetate, calcium hydroxide, calcium carbonate, calcium lactate, calcium sulfate 1 or 2 of alkaline earth metal salts such as magnesium chloride, magnesium formate, magnesium succinate, magnesium butyrate, magnesium oxalate, magnesium stearate, magnesium phosphate, magnesium nitrate, magnesium acetate, magnesium hydroxide, magnesium carbonate More than one species may be combined with the titanium compound.

  Furthermore, when using the copolymer polyethylene naphthalate composition of this invention, the flame-retardant effect of a copolymer polyethylene naphthalate composition can further be heightened by using a flame retardant together. For example, triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, triethyl phosphate, cresyl diphenyl phosphate, xylenyl diphenyl phosphate, cresyl bis (2,6-xylenyl) phosphate, 2-ethylhexyl Phosphate, dimethylmethyl phosphate, resorcinol bis (diphenyl) phosphate, bisphenol A bis (diphenyl) phosphate, bisphenol A bis (dicresyl) phosphate, diethyl-N, N-bis (2-hydroxyethyl) aminomethyl phosphate Phosphorus flame retardants such as phosphate, phosphoric acid amide, organic phosphine oxide, red phosphorus, ammonium polyphosphate, phosphazene, cyclophosphazene, triazine, mela Nitrogen-based flame retardants such as cyanurate, succinoguanamine, ethylene dimelamine, triguanamine, triazinyl cyanurate, melem, melam, tris (β-cyanoethyl) isocyanurate, acetoguanamine, guanylmelamine sulfate, melem sulfate, melam sulfate, Metal salt flame retardants such as potassium diphenylsulfone-3-sulfonate, aromatic sulfonimide metal salt, alkali metal salt of polystyrene sulfonate, aluminum hydroxide, magnesium hydroxide, dolomite, hydrotalcite, barium hydroxide, basic Hydrated metal flame retardants such as magnesium carbonate, zirconium hydroxide, tin oxide, silica, aluminum oxide, iron oxide, titanium oxide, manganese oxide, magnesium oxide, zirconium oxide, zinc oxide, molybdenum oxide, cobalt oxide , Bismuth oxide, chromium oxide, tin oxide, antimony oxide, nickel oxide, copper oxide, tungsten oxide, zinc borate, zinc metaborate, barium metaborate, zinc carbonate, magnesium carbonate, calcium carbonate, zinc barium stannate Silicone flame retardants such as flame retardant and silicone powder. Higher flame retardant effect can be obtained from the combined effect of the flame retardant mechanism of the high flame retardancy of the phosphorus compound-containing resin itself and the flame retardant.

  The intrinsic viscosity of the copolymerized polyethylene naphthalate constituting the flame-retardant transparent copolymerized polyethylene naphthalate obtained by the present invention must be 0.50 dL / g or more from the viewpoint of mechanical strength and moldability. .50 to 0.70 dL / g is preferable. When the intrinsic viscosity is less than 0.50 dL / g, the mechanical strength is inferior, and when it exceeds 0.70 dL / g, the fluidity is lowered and the molding processability is inferior. In order to make the intrinsic viscosity within the range of this value, the ethylene glycol amount calculated by subtracting from the copolymerization ratio of the compound represented by the above formula (I) during the production of the copolyester, It is important to use an excess amount of ethylene glycol. In the copolymerized polyethylene naphthalate of the present invention, the glass transition temperature is preferably 80 ° C. or higher, more preferably 100 ° C. or higher. This range of glass transition temperature values can be achieved by a sufficient intrinsic viscosity value and a copolymerization rate of the compound represented by the above formula (I).

  The surface hardness of the flame retardant transparent copolymer polyethylene naphthalate composition obtained by the present invention needs to be H or higher in pencil hardness from the viewpoint of the physical properties of the molded product. If the surface hardness is less than H in pencil hardness, it is not preferable because the surface of the molded product is easily scratched and is not suitable for optical use. In order to make the surface hardness within the range of this value, when producing the flame-retardant transparent copolymerized polyethylene naphthalate, the range of the surface hardness value depends on the copolymerization rate of the compound represented by the formula (I). Can be achieved.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to a following example, unless the summary is exceeded. The physical properties of the obtained flame retardant transparent polyester composition were measured by the following methods.

1) Intrinsic Viscosity (IV) Measurement It was measured at 35 ° C. in orthochlorophenol as a solvent according to a conventional method.

2) Glass transition temperature measurement Flame retardant polyethylene naphthalate dried under reduced pressure at 25 ° C. for 24 hours was measured using a differential scanning calorimeter (DSC) while increasing the temperature at a temperature increase rate of 10 ° C./min. About 10 mg of a measurement sample was weighed in an aluminum pan (TA Instruments) and measured under a nitrogen atmosphere.

3) Phosphorus atom concentration measurement The phosphorus atom concentration in the polyester obtained by the polymerization was measured by fluorescent X-rays (manufactured by Rigaku, Rataflex RU200).

4) Flame retardancy test The flame retardancy test was conducted according to the flame retardancy test method of UL94.

5) Transmittance measurement The flame-retardant transparent polyester obtained by the present invention was molded into a 3 cm square flat plate (thickness 3 mm) and confirmed with a haze meter. A haze of 11% or less was rated as ◯, and a cloudiness exceeding 12% was rated as x.

6) Measurement of solvent resistance A 3 cm square (thickness 3 mm) flat plate measured for haze measurement was immersed in acetone, chloroform, chlorobenzene and m-cresol at 25 ° C. for 48 hours. It was confirmed whether there was a change in appearance when immersed. The case where it did not dissolve at all was indicated as ◯, the case where it whitened but did not swell, □, the case where it swelled as Δ, and the case where it dissolved as ×.

7) Surface hardness (pencil hardness) measurement The flame-retardant transparent polyester obtained by the present invention was made into a 5 cm square flat plate (thickness 3 mm), and this was measured according to JISK5401. The pencil hardness was H or higher, and the H or lower was X.

[Example 1]
The total amount of 2,6-naphthalenedicarboxylic acid dimethyl ester as divalent dicarboxylic acid is 30.3 kg, ethylene glycol is 15.4 kg as divalent diol, and anhydrous calcium acetate is used as a transesterification catalyst with respect to the number of moles of divalent dicarboxylic acid. 20 mmol% and anhydrous magnesium acetate as a total amount of 50 mmol% with respect to the number of moles of divalent dicarboxylic acid, and the ester exchange reaction was carried out for 180 minutes while raising the reaction temperature to 218 ° C. or higher. Subsequently, tetra-n-butyl titanate as a polymerization catalyst was added to the resulting reaction product in a total amount of 5 mmol% with respect to the number of moles of divalent dicarboxylic acid, and triethyl phosphonoacetate (hereinafter referred to as TEPA) as a thermal stabilizer. Is added in an amount of 50 mmol% as a total amount with respect to the number of moles of the divalent dicarboxylic acid, and 9.0 kg of a compound represented by the above formula (I) as a flame retardant (hereinafter sometimes referred to as M-Ester) is added. The polycondensation reaction was started by moving to a polycondensation reaction tank.
The polycondensation reaction is gradually reduced from normal pressure to 0.133 kPa (1 Torr) over 40 minutes, and simultaneously raised to a predetermined reaction temperature 295. Thereafter, a predetermined polymerization temperature, 0.133 kPa (1 Torr) is maintained. The polycondensation reaction was carried out for 30 minutes while maintaining.
When 180 minutes have elapsed from the start of the polycondensation reaction, the polycondensation reaction is completed and the copolymer polyester is extracted, and the intrinsic viscosity, glass transition temperature, flame retardancy, haze, solvent resistance, resin surface hardness (pencil hardness) The impact resistance was measured, and the results are shown in Table 1.

[Example 2]
A copolymer polyethylene naphthalate was obtained in the same manner as in Example 1 except that tetra-n-butyl titanate was changed to 10 mmol%. The obtained copolyester was extracted, and the intrinsic viscosity, glass transition temperature, flame retardancy, haze, and resin surface hardness (pencil hardness) were measured. The results are shown in Table 1.

[Comparative Example 1]
Polyethylene naphthalate was obtained in the same manner as in Example 1 except that M-Ester was not added. The obtained copolyester was extracted, and the intrinsic viscosity, glass transition temperature, flame retardancy, haze, and resin surface hardness (pencil hardness) were measured. The results are shown in Table 1.

[Comparative Example 2]
A copolyester was obtained in the same manner as in Example 1 except that M-Ester was changed to other than 4.5 kg. The obtained copolyester was extracted, and the intrinsic viscosity, glass transition temperature, flame retardancy, haze, and resin surface hardness (pencil hardness) were measured. The results are shown in Table 1.

[Comparative Example 3]
A copolyester was obtained in the same manner as in Example 1 except that M-Ester was changed to other than 10.0 kg. The obtained copolyester was extracted, and the intrinsic viscosity, glass transition temperature, flame retardancy, haze, and resin surface hardness (pencil hardness) were measured. The results are shown in Table 1.

[Comparative Example 4]
A copolymer polyester was obtained in the same manner as in Example 1 except that ethylene glycol was changed to other than 11.5 kg. The obtained copolyester was extracted, and the intrinsic viscosity, glass transition temperature, flame retardancy, haze, and resin surface hardness (pencil hardness) were measured. The results are shown in Table 1.

[Comparative Example 5]
A copolyester was obtained in the same manner as in Example 1 except that TEPA was not added. The obtained copolyester was extracted, and the intrinsic viscosity, glass transition temperature, flame retardancy, haze, and resin surface hardness (pencil hardness) were measured. The results are shown in Table 1.

[Comparative Example 6]
A copolymer polyester was obtained in the same manner as in Example 1 except that 22.9 kg of dimethyl terephthalate, 12.8 kg of ethylene glycol, and M-Ester were changed to other than 6.8 kg. The obtained copolyester was extracted, and the intrinsic viscosity, glass transition temperature, flame retardancy, haze, and resin surface hardness (pencil hardness) were measured. The results are shown in Table 1.

  The copolymerized polyethylene naphthalate composition in the present invention is characterized in that the copolymerized polyethylene naphthalate resin molded article has good flame retardancy, transparency, chemical resistance and surface hardness. Things can be provided. It is industrially significant to be able to provide a polyethylene naphthalate composition having excellent physical properties such as flame resistance, transparency and chemical resistance, as well as the high heat resistance of such polyethylene naphthalate.

Claims (5)

A polyethylene naphthalate composition obtained by copolymerizing a phosphorus compound represented by the following formula (I), wherein the intrinsic viscosity of the copolymerized polyethylene naphthalate is 0.50 dL / g or more in the copolymerized polyethylene naphthalate composition. The phosphorus atom content of 10000 to 13000 ppm, and further containing 10 to 200 mmol% of a phosphorus compound represented by the following formula (II) with respect to the divalent carboxylic acid constituting the copolymerized polyethylene naphthalate Polyethylene naphthalate composition.

[Wherein, R ⁵ , R ⁶ and R ⁷ are the same or different and each represents an alkyl group having 1 to 4 carbon atoms, X represents —CH ₂ — or —CH (Y) (Y represents Benzene ring). ]   The copolymer polyethylene naphthalate composition according to claim 1, having a glass transition temperature of 100 ° C or higher.   The copolymer polyethylene naphthalate composition according to claim 1 or 2, wherein the content of phosphorus atoms in the copolymer polyethylene naphthalate composition is 11000 to 13000 ppm.   The copolymer polyethylene naphthalate composition according to claim 1, wherein the surface hardness is H or more in pencil hardness. The copolymer polyethylene naphthalate composition according to any one of claims 1 to 4, further comprising a titanium compound represented by the following formula (III).

[In the above formula, R ¹ , R ² , R ³ And R ⁴ Are the same or different and each represents an alkyl group or
Represents a phenyl group, m represents an integer of 1 to 4, and when m is 2, 3 or 4, 2, 3 or 4 R ² And R ³ May be the same or different from each other. ]