JP2013173869A - Flame retardant polyester composition, and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flame retardant polyester composition excellent in flame retardancy and hydrolysis resistance, excellent in heat resistance, and improved in polymerization reactivity.SOLUTION: A polyester composition contains 1 to 25 mol% of a component derived from a phosphine oxide compound represented by formula (1) based on the total dicarboxylic acid component of a polyester, wherein the polyester composition contains 50 ppm to 400 ppm of titanium compounds in terms of titanium atom, and 25 ppm to 600 ppm of magnesium compounds in terms of magnesium atom. In the formula, Ris hydrogen, a 1-12C monovalent saturated hydrocarbon or a monovalent aromatic hydrocarbon, and m and n are each an integer of 1 to 6.

Description

  The present invention relates to a flame retardant polyester composition having excellent flame retardancy when formed into a molded article such as a film, and further having excellent hydrolysis resistance and heat resistance.

  Polyesters, particularly polyethylene terephthalate and polyethylene naphthalate, are widely used in fibers, films and other molded articles because of their excellent mechanical, physical and chemical performance. In recent years, with the enforcement of the Product Liability Act, there is an increasing demand for resin flame retardants to ensure fire safety.

Conventionally used polyester resins containing halogen-based flame retardants are desired to be environment-friendly flame retardants that do not contain halogens, for example, because they generate gases such as hydrogen halides during combustion.
For this reason, non-halogen flame retardants such as phosphate ester flame retardants have been proposed (Patent Document 1). However, it is necessary to increase the amount of these flame retardants in order to exhibit sufficient flame retardancy, resulting in a decrease in mechanical properties of the resulting molded product, or the flame retardants from the polyester resin. Or bleed out.

On the other hand, various reactive flame retardants that are chemically bonded to polyester resins have been proposed, and in particular, copolymerization of phosphorus compounds is known (Patent Documents 1 and 2). However, although these compounds have improved flame retardancy, the copolymerized polyester has a problem that the hydrolysis resistance is significantly reduced. Thus, Patent Document 3 exemplifies various phosphine oxide compounds having hydroxyl groups at both ends, in which excellent flame retardancy and improved hydrolysis resistance are described.
However, there is a problem in the reactivity and heat resistance of the above compounds, and there is a demand for a highly practical resin that maintains not only the flame retardancy and hydrolysis resistance but also various characteristics inherent in polyester.

Japanese Patent Laid-Open No. 50-56488 JP 2000-319368 A Japanese Patent Laid-Open No. 10-25338

  An object of the present invention is to provide a flame retardant having excellent heat resistance and improved polymerization reactivity while copolymerizing a phosphine oxide compound having hydroxyl groups excellent in hydrolysis resistance at both ends as a flame retardant. It is in providing a conductive polyester composition.

  As a result of diligent research to solve the above-mentioned problems, the present inventors have found that a magnesium compound is used as a titanium compound used as a catalyst when producing a polyester composition obtained by copolymerizing a phosphine oxide compound having hydroxyl groups at both ends. It has been found that excellent flame retardancy, hydrolysis resistance and polymerization reactivity can be obtained by adding.

  That is, an object of the present invention is a flame retardant polyester composition containing 1 to 25 mol% of a component derived from a phosphine oxide compound represented by the following formula (1) based on the number of moles of all acid components of the polyester. There is provided a flame retardant polyester composition containing 50 ppm to 400 ppm of a titanium compound as a titanium atom and 25 ppm to 600 ppm of a magnesium compound as a magnesium atom.

（式中、Ｒ_１は水素、炭素数１〜１２の１価の飽和炭化水素または１価の芳香族炭化水素のいずれか１つを表し、ｍ、ｎはそれぞれ１〜６の整数を表す）

(In the formula, R ₁ represents any _one of hydrogen, a monovalent saturated hydrocarbon having 1 to 12 carbon atoms or a monovalent aromatic hydrocarbon, and m and n each represents an integer of 1 to 6)

Moreover, the flame-retardant polyester composition of the present invention has, as a preferred form thereof, a ratio of the amount of titanium compound atoms to magnesium atoms contained in a ratio of 0.5 <Ti / Mg <3.0.
It is included that the titanium compound to be contained is a product obtained by reacting a compound represented by the following general formula (2) with an aromatic polycarboxylic acid or an anhydride thereof.
Ti (OR) ₄ (2)
(In the above formula, R represents an alkyl group and / or a phenyl group)

Furthermore, it is a manufacturing method of the polyester composition which has 1-25 mol% of components induced | guided | derived from the phosphine oxide compound represented by the said Formula (1),
The polycondensation reaction is carried out in the presence of a titanium compound and a magnesium compound, and based on the mass of the resulting polyester, it is difficult to set the titanium compound in the range of 50 ppm to 400 ppm in terms of titanium atoms and the magnesium compound in the range of 25 ppm to 600 ppm in terms of magnesium atoms. A method for producing a flammable polyester composition is also provided.

  The flame-retardant polyester composition of the present invention has excellent heat resistance and copolymerization reactivity as a flame retardant while copolymerizing a phosphine oxide compound having hydroxyl groups excellent in hydrolysis resistance at both ends. It has been improved and can be suitably used as a molded article such as a film, and can be suitably used for various applications that require flame retardancy, such as electrical and electronic applications such as flexible printed circuit boards.

The flame retardant polyester composition in the present invention will be described in detail.
The polyester in the present invention contains 1 to 25 mol of a component derived from a phosphine oxide compound represented by the following formula (1) based on all diol components of the polyester (hereinafter sometimes referred to as phosphorus-containing copolymer unit). % In the range.

（式中、Ｒ_１は水素、炭素数１〜１２の１価の飽和炭化水素または１価の芳香族炭化水素のいずれか１つを表し、ｍ、ｎはそれぞれ１〜６の整数を表す）

(In the formula, R ₁ represents any _one of hydrogen, a monovalent saturated hydrocarbon having 1 to 12 carbon atoms or a monovalent aromatic hydrocarbon, and m and n each represents an integer of 1 to 6)

Among the units composed of the phosphine oxide compound represented by the formula (1), the number of methylene chains represented by m and n is preferably 1 to 4, and more preferably 2 to 3.
Moreover, among the units consisting of the phosphine oxide compound represented by the formula (1), among the substituents represented by R ₁ , preferred are C 1-6 saturated hydrocarbons and phenyl groups.

  In the present invention, it is necessary to use a phosphine oxide compound as a flame retardant imparting component, and among the phosphine oxide compounds, it is necessary to use a diol compound or a derivative thereof in a monomer state. If a phosphorus-containing copolymer unit derived from a compound other than a phosphine oxide compound is present in the polyester main chain, for example, a phosphorus compound polymer unit derived from phosphinic acid or phosphonic acid ester, the heat resistance and hydrolysis resistance of the polyester composition are adversely affected. Effect. Also in the phosphine oxide compound, when a dicarboxylic acid compound or a derivative thereof is used as a monomer component, hydrolysis resistance as high as that of a diol type phosphine oxide compound cannot be obtained.

  The content of the phosphine oxide represented by the above formula (1) in the flame retardant polyester composition of the present invention is in the range of 1 mol% or more and 25 mol% or less based on the number of moles of all acid components of the polyester. is there. The preferred lower limit is 3 mol%, further 5 mol%, and the preferred upper limit is 15 mol%, further 10 mol%, especially 8 mol%. If the content of the phosphorus-containing copolymer unit is less than the lower limit value, the flame retardancy targeted by the present invention cannot be obtained. Further, if the content of the phosphorus-containing copolymer unit exceeds the upper limit, a problem occurs in the polymerization reactivity, and sufficient mechanical properties when formed into a molded body such as a film cannot be obtained.

  As a result of copolymerizing the monomer component comprising the phosphine oxide compound, the phosphorus atom concentration in the polyester composition is 0.5% by mass or more and 3.0% by mass or less, and further 0.5% by mass based on the mass of the polyester. % Or more and 2.0% by mass or less is preferable in order to obtain the flame retardancy targeted by the present invention.

  The main repeating units of the polyester resin in the present invention are dicarboxylic acid components such as terephthalic acid and 2,6-naphthalenedicarboxylic acid, ethylene glycol, trimethylene glycol, tetramethylene glycol, hexamethylene glycol, cyclohexane-1,4-di Consists of diol components such as methanol. Here, “main” means 50 mol% or more of all repeating units, more preferably 70 mol% or more, more preferably 75 mol% or more, particularly preferably 80 mol% or more, and most preferably 85 mol%. More than mol%.

  The polyester resin in the present invention can contain other copolymerization components as long as the obtained properties are not largely changed. Other copolymer components are not particularly limited, but as dicarboxylic acid components, isophthalic acid, terephthalic acid, orthophthalic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, Components other than the main component from aromatic dicarboxylic acid components such as 4,4'-biphenyldicarboxylic acid, alicyclic dicarboxylic acid components such as cyclohexane-1,4-dicarboxylic acid, fats such as succinic acid, adipic acid, and sebacic acid As diol components such as aliphatic dicarboxylic acid components, components other than main components from aliphatic diol components such as ethylene glycol, propylene glycol and trimethylene glycol, alicyclic diol components such as cyclohexane-1,4-dimethanol, and bisphenol A Aromatic diol components, such as Ethylene glycol, polyethylene glycol, and ether condensed diol component and polytetramethylene glycol. Moreover, as components other than the above-mentioned preferable dicarboxylic acid and diol components, a tri- or higher functional component such as a hydroxycarboxylic acid component such as p-hydroxybenzoic acid, trimellitic acid, and pyromellitic acid can be given.

  The flame-retardant polyester composition of the present invention can be used for either esterification reaction of dicarboxylic acid and glycol or ester exchange reaction of lower alkyl ester of dicarboxylic acid and glycol. As the transesterification reaction catalyst, one or more of compounds containing manganese, magnesium, calcium, zinc, sodium, potassium, cobalt, and titanium can be used.

However, the flame-retardant polyester composition of the present invention is required to use a titanium compound as a polycondensation catalyst in the polycondensation reaction, and in this case, a magnesium compound must be present. is there. The conventional polycondensation catalyst, such as antimony compounds such as antimony trioxide and germanium compounds represented by germanium dioxide, may cause problems that the degree of polymerization does not increase sufficiently, or the reaction is carried out only with titanium compounds. As a result, it takes a long time to reach the desired degree of polymerization, resulting in poor production efficiency. Examples of the titanium compound used in the present invention include titanium acetate and tetra-n-butoxytitanium. Particularly desirable is a compound represented by the following general formula (2) and an aromatic polyvalent carboxylic acid or anhydride thereof. It is a product obtained by reacting a product.
Ti (OR) ₄ (2)
(In the above formula, R represents an alkyl group and / or a phenyl group)

  The tetraalkoxide titanium represented by the general formula (2) is not particularly limited as long as R is an alkyl group and / or a phenyl group, but tetraisopropoxy titanium, tetrapropoxy titanium, tetra-n-butoxy titanium, tetra Ethoxy titanium, tetraphenoxy titanium and the like are preferably used. Further, as the aromatic polyvalent carboxylic acid to be reacted with such a titanium compound or an anhydride thereof, phthalic acid, trimellitic acid, hemimellitic acid, pyromellitic acid and anhydrides thereof are preferably used. When the titanium compound and the aromatic polyvalent carboxylic acid or its anhydride are reacted, the aromatic polyvalent carboxylic acid or a part of its anhydride is dissolved in a solvent, and the titanium compound is dropped into this, What is necessary is just to make it react for 30 minutes or more at the temperature of 0-200 degreeC. By using this product, deactivation of the catalytic function of the titanium catalyst compound by the phosphine oxide compound decomposed during the polycondensation reaction can be suppressed.

  The flame retardant polyester composition of the present invention needs to contain the titanium compound soluble in the polymer in the range of 50 to 400 ppm in terms of titanium metal atomic weight based on the mass of the flame retardant polyester composition. . Particularly preferred lower limit values are 100 ppm and further 140 ppm, and particularly preferred upper limit values are 250 ppm and further 240 ppm. When the titanium atom weight is less than the lower limit, the productivity of the polyester is lowered, and a polyester having a target molecular weight cannot be obtained. On the other hand, when the titanium atomic weight exceeds the upper limit, the thermal stability tends to be lowered.

  In addition, the flame retardant polyester composition of the present invention contains a magnesium compound represented by magnesium acetate in order to improve the polymerization reactivity, together with 25 ppm to 600 ppm in terms of magnesium atomic weight based on the mass of the flame retardant polyester. There is a need to. The preferred lower limit is 50 ppm and further 80 ppm, and the preferred upper limit is 300 ppm and further 250 ppm. By including the magnesium compound together with the titanium compound, it is possible to compensate for the decrease in the polycondensation reaction rate due to the deactivation of the titanium compound due to the decomposition of the phosphorus compound. While the condensation reaction must be performed, the effect of shortening the polycondensation reaction time can be obtained even at the same reaction temperature. If the magnesium atomic weight is less than the lower limit, the above-described effect is hardly obtained, and if the magnesium atomic weight exceeds the upper limit, the thermal stability may be lowered, which is not preferable from the viewpoint of cost.

Moreover, the mass ratio of the titanium atom to be contained and the magnesium atom is
0.5 <Mg / Ti <3.0
It is preferable that it exists in the range. When this ratio is in the above range, the polymerization reactivity can be further improved. In the above formula, Ti is the titanium atomic weight, and Mg is the magnesium atomic weight. The lower limit value of Mg / Ti is preferably 0.8, and the upper limit value is 2.5.

The intrinsic viscosity of the polyester in the flame-retardant polyester composition of the present invention (measured at a temperature of 35 ° C. using a mixed solvent of P-chlorophenol / 1,1,2,2-tetrachloroethane having a weight ratio of 4/6) is 0. It is preferably from 60 dl / g to 1.5 dl / g, more preferably from 0.65 dl / g to 1.0 dl / g. If the intrinsic viscosity of the polyester is less than the lower limit, the mechanical properties of the molded product will not be satisfied. On the other hand, if the upper limit value is exceeded, the melt viscosity is high, so that melt extrusion during molding becomes difficult.
In addition, various conventionally known additives may be included within a range that does not impair the object of the present invention. For example, organic or inorganic lubricant particles, colorants, antistatic agents, antioxidants, ultraviolet absorbers, etc. Can be mentioned.

  Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. In the present invention, the characteristics were measured and evaluated by the following methods.

(1) Intrinsic viscosity The intrinsic viscosity of the obtained polyester was measured at 35 ° C by dissolving the polymer using a mixed solvent of P-chlorophenol / 1,1,2,2-tetrachloroethane (40/60 weight ratio). And asked. The unit is dl / g.

(2) Amount of copolymerization of components derived from phosphine oxide 20 mg of a sample was dissolved in 0.6 mL of a mixed solvent of deuterated trifluoroacetic acid: deuterated chloroform = 1: 1, and ¹ H-NMR spectrum (JEOL made by JEOL Ltd.) was obtained at room temperature. A600) was measured. From the NMR spectrum, the proportion of components derived from phosphine oxide was estimated.

(3) Content of Titanium Atom and Phosphorus A polymer sample was heated and melted to prepare a circular disk, which was measured using a fluorescent X-ray apparatus 3270 type manufactured by Rigaku and quantified.

(4) Content of magnesium atom A polymer sample dissolved in orthochlorophenol and then decomposed with 0.5N hydrochloric acid was measured using a polarization Zeeman atomic absorption spectrophotometer Z5000 manufactured by Hitachi, Ltd. and quantified.

(5) Flammability Film samples were evaluated according to the UL-94 VTM method. The sample was cut into 20 cm × 5 cm and left in 23 ± 2 ° C. and 50 ± 5% RH for 48 hours, and then the lower end of the sample was held 10 mm above the burner and held vertically. The bottom of the sample was indirectly fired for 3 seconds using a Bunsen burner having an inner diameter of 9.5 mm and a flame length of 20 mm as a heating source. Flame retardance was evaluated according to the evaluation criteria of VTM-0, VTM-1, and VTM-2, and among the number of measurements of n = 5, the rank having the same number of ranks was set.

[Example 1]
Dimethyl terephthalate (DMT) 31 kg (160 mol), ethylene glycol (EG) 16.2 kg (261 mol), n-butyl-bis (3-hydroxytrimethylene) phosphine oxide (Nippon Kagaku Kogyo Co., Ltd. PO-) 4500) 2.45 Kg (11 mol) was charged into a reaction vessel equipped with a stirrer, a rectifying column, and a cooler, and as a catalyst, 30 mmol% of manganese acetate tetrahydrate (based on the total acid components). In addition, a transesterification reaction was performed. Subsequently, a reaction product obtained by reacting titanium tetrabutoxide and trimellitic anhydride at a molar ratio of 1: 2 at 175 ° C. for 4 hours (titanium trimellitic acid) 80 mmol% (based on all acid components), magnesium acetate 120 A mmol% (based on the total acid components) was added, and a polycondensation reaction was performed at 265 ° C. under vacuum. A polycondensation reaction was performed for 225 minutes to obtain a polyester composition having an intrinsic viscosity of 0.630 dl / g.
The obtained polyester composition was dried with a 170 ° C. dryer for 3 hours, and melt-extruded on a rotating drum maintained at a surface temperature of 20 ° C. from a die at 270 ° C. to form an unstretched film having a thickness of 630 μm. This unstretched film is preheated to 75 ° C and stretched 4.1 times in the film forming direction (MD direction) while being heated by a single infrared heater with a surface temperature of 800 ° C from above 15 mm between the low speed roller and the high speed roller. Further, the film was stretched 4.2 times in the direction (TD direction) perpendicular to the film forming direction in an atmosphere heated at 100 ° C. while holding both ends of the film stretched longitudinally, and further fixed in the transverse direction. Heat treatment was performed at 220 ° C. while giving relaxation of 3% of the full width to obtain a film having a thickness of 50 μm.
Table 1 shows the properties of the obtained polyester composition and the film sample comprising the same.

[Examples 2 to 4]
In Example 1, it carried out like Example 1 except having changed the addition amount of the phosphorus compound, the addition amount of the titanium compound, the addition amount of the magnesium compound, and the polycondensation temperature. Table 1 shows the properties of the obtained polyester composition and the film sample comprising the same. The characteristics are shown in Table 1.

[Example 5]
Dimethyl 2,6-naphthalenedicarboxylate (NDC) 35 kg (143 mol), ethylene glycol (EG) 17.1 kg (276 mol), bis (3-hydroxytrimethylene) n-butylphosphine oxide (Nippon Chemical Industry Co., Ltd., PO- 4500) 2.19 Kg (9.9 mol) was charged into a reaction vessel equipped with a stirrer, a rectifying column and a cooler, and as a catalyst, manganese acetate tetrahydrate was added at 30 mmol% (based on the total acid components). In addition, a transesterification reaction was performed. Subsequently, a reaction product obtained by reacting titanium tetrabutoxide and trimellitic anhydride at a molar ratio of 1: 2 at 175 ° C. for 4 hours (titanium trimellitic acid) 80 mmol% (based on all acid components), magnesium acetate 80 A mmol% (based on the total acid components) was added, and a polycondensation reaction was performed at 270 ° C. under vacuum. A polycondensation reaction was performed for 240 minutes to obtain a polyester composition having an intrinsic viscosity of 0.61 dl / g.
In film formation, a film sample was obtained in the same manner as in Example 1 except that the preheating temperature in MD direction stretching was 120 ° C. and the temperature in TD direction stretching was 140 ° C.
Table 1 shows the properties of the obtained polyester composition and the film sample comprising the same.

[Example 6]
Terephthalic acid (TA) 26.6 Kg (160 mol) and ethylene glycol (EG) 16.1 Kg (260 mol) were charged into a reaction vessel equipped with a stirrer, a rectifying column, and a cooler, under a gauge pressure of 0.15 MPa, 140 After the esterification reaction while raising the temperature from 250C to 250C, n-butyl-bis (3-hydroxytrimethylene) phosphine oxide (Nippon Kagaku Kogyo Co., Ltd. PO-4500) 2.45 Kg (11 mol) is used as the phosphorus compound. And a reaction product of titanium tetrabutoxide and trimellitic anhydride at a molar ratio of 1: 2 at 175 ° C. for 4 hours (titanium trimellitic acid) 80 mmol% (based on all acid components), magnesium acetate 120 mmol % (Based on the total acid components) was added, and a polycondensation reaction was performed at 265 ° C. under vacuum. A polycondensation reaction was performed for 235 minutes to obtain a polyester composition having an intrinsic viscosity of 0.63 dl / g. Thereafter, a film having a thickness of 50 μm was obtained. Table 1 shows the properties of the obtained polyester composition and the film sample comprising the same.

[Comparative Examples 1 to 9]
The same procedure as in Example 1 was conducted except that the addition amount of the phosphorus compound, the addition amount of the polycondensation reaction catalyst and magnesium acetate, the polycondensation reaction temperature, the post-treatment reaction temperature, and the time were changed. Table 1 shows the properties of the obtained polyester composition and the film sample comprising the same. In addition, what stopped the raise of the polymerization degree on the way has terminated reaction on the way. In Comparative Example 4, as shown in Table 1, diantimony trioxide was added as a polycondensation reaction catalyst so that the amount of elemental antimony was 202 ppm.

  The meaning of * in Table 1 is the time when the stirring power stops increasing and the degree of polymerization no longer increases.

  The flame-retardant polyester composition of the present invention can be suitably used for various applications that require flame retardancy, such as electrical and electronic applications such as flexible printed circuit boards.

Claims (4)

A polyester composition containing 1 to 25 mol% of a component derived from a phosphine oxide compound represented by the following formula (1) on the basis of all dicarboxylic acid components of polyester, and containing 50 ppm to 400 ppm of titanium compound as titanium atom And a flame retardant polyester composition containing 25 ppm to 600 ppm of a magnesium compound as magnesium atoms.

(In the formula, R ₁ represents any _one of hydrogen, a monovalent saturated hydrocarbon having 1 to 12 carbon atoms or a monovalent aromatic hydrocarbon, and m and n each represents an integer of 1 to 6) Ratio of amount of titanium atom and magnesium atom contained is 0.5 <Ti / Mg <3.0
The flame-retardant polyester composition according to claim 1, which is in the range of The flame retardant polyester composition according to claim 1, wherein the titanium compound contained is a product obtained by reacting a compound represented by the following general formula (2) with an aromatic polyvalent carboxylic acid or an anhydride thereof.
Ti (OR) ₄ (2)
(In the above formula, R represents an alkyl group and / or a phenyl group) A method for producing a polyester composition having 1 to 25 mol% of a component derived from a phosphine oxide compound represented by the following formula (1):
The polycondensation reaction is carried out in the presence of a titanium compound and a magnesium compound, and based on the mass of the resulting polyester, it is difficult to set the titanium compound in the range of 50 ppm to 400 ppm in terms of titanium atoms and the magnesium compound in the range of 25 ppm to 600 ppm in terms of magnesium atoms. A method for producing a flammable polyester composition.

(In the formula, R ₁ represents any _one of hydrogen, a monovalent saturated hydrocarbon having 1 to 12 carbon atoms or a monovalent aromatic hydrocarbon, and m and n each represents an integer of 1 to 6)