JPH08311313A - Aromatic polyester composition and molded product - Google Patents

Abstract

PURPOSE: To obtain the subject composition excellent in hydrolysis resistance and the heat resistance and hue when melted, and extremely low in large-sized insoluble foreign matter content, containing each specific chlorophosphoric acid-containing ester and metal compound in specific proportions. CONSTITUTION: This composition is obtained by blending (A) an aromatic polyester with (B) a chlorophosphoric acid-containing ester of the formula (R<1> to R<3> are each an alkoxide chloroalkoxide group, etc., where at least one of R<1> to R<3> is a chloroalkoxide group) and (C) a metal compound selected from the compounds of metals belonging to I, II, VII, and VIII Groups inn the third and frourth periods of the periodic table, so that the content of the component B is 3 to 50ppm in terms of phosphorus atom, and that the component C satisfies the relationship: P-M<=10 [P is the content (mmol%) of the component B based on the dibasic acid component constituting the component A; M is the content (mmol%) of the component C based on the dibasic acid component]. The component B is pref. a compound of the formula wherein R<1> to R<3> are all chloroalkoxide groups, [e.g. tris(chloroethyl) phosphate].

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to aromatic polyester compositions and molded articles therefrom. For more information,
The present invention relates to an aromatic polyester composition which is excellent in hydrolysis resistance, heat resistance upon melting and hue and, in addition, has an extremely small size of foreign substances generated during synthesis of an aromatic polyester, and a molded product made from the aromatic polyester composition.

[0002]

BACKGROUND OF THE INVENTION Aromatic polyesters, especially polyethylene terephthalate, have many excellent properties,
It is widely used for various purposes, especially for fibers and films. Such an aromatic polyester is usually prepared by esterification of terephthalic acid and ethylene glycol, transesterification reaction of dialkyl terephthalate and ethylene glycol, or reaction of terephthalic acid and ethylene oxide. It is produced by producing an ethylene glycol ester and / or a low polymer thereof, and then heating the product under reduced pressure to cause a polycondensation reaction until a predetermined degree of polymerization is reached.

The polyester thus obtained is
It is put into practical use by extruding it in a molten state from fine holes (spinning holes) or slits into a fibrous or film shape, and then stretching. Polyester is often held in a molten state at a high temperature for a long time during the polycondensation reaction during the production process and during the formation process. In order to prevent thermal decomposition during that period and to obtain a polyester molded product with good quality, especially color tone, Phosphorus compounds such as phosphoric acid, phosphorous acid, lower alkyl esters and aryl esters thereof are generally used.

However, polyesters which are sufficiently satisfactory in heat resistance and color tone have not yet been obtained, and further improvement is demanded. On the other hand, polyester moldings are often used under wet heat conditions, and in this case, there are problems such as reduction in strength due to hydrolysis and deterioration in hue. For example, improvement in hydrolysis resistance of polyester is demanded as a filtration filter or a canvas for paper making in industrial use, and as a surgical gown or uniform in a pharmaceutical factory in clothing use.

Conventionally, various techniques for reducing the concentration of terminal carboxyl groups of polyester have been proposed in order to improve the hydrolysis resistance of polyester. For example, Japanese Patent Publication Sho 44
No. 27911 and JP-A No. 54-6051 disclose a method of adding a certain type of epoxy compound to reduce the terminal carboxyl group concentration of a polyester. However, in these methods, the reactivity of the epoxy compound is low and the effect is small.

Further, Japanese Patent Publication No. 38-152220 or Japanese Patent Publication No. 46-5389 discloses a method of adding a carbodiimide such as polycarbodiimide or biscarbodiimide to lower the terminal carboxyl group of polyester. Carbodiimide itself is liable to undergo thermal modification and may cause coloration or deterioration of physical properties of the polyester depending on the reaction conditions, and thus its use requires careful attention.

On the other hand, in order to improve the hydrolysis resistance in a wide range of applications of polyesters, from thick denier for industrial use to fine denier for clothing, it is necessary to improve the properties of the polyester itself. Further, in the polyester, fine insoluble foreign matters are present, but it was found that most of them were particles composed of the used transesterification catalyst, polymerization catalyst and stabilizer when analyzed. These insoluble foreign matters cause various troubles during the molding process of polyester, particularly when extruding into a fiber or film and stretching. In particular, recently, fibers made of polyester,
There are many demands for films such as fine denier, thinning, and higher quality, and attempts have been made to increase the speed of spinning and molding in order to improve productivity. Molding is a serious obstacle in any case.

[0008]

SUMMARY OF THE INVENTION The present invention has been made to solve the problems due to the stability and durability of the aromatic polyester, and its purpose is to provide hydrolysis resistance,
It is an object of the present invention to provide a polyester composition which is excellent in heat resistance and hue during melting and drying, has a small amount of large insoluble foreign matters in a polymer, and has improved moldability and quality.

[0009]

Means for Solving the Problems As a result of repeated studies for achieving the above-mentioned object of the present invention, the present inventors have found that the type of phosphorus compound used as a stabilizer is hydrolysis resistance, heat resistance and hue of polyester. And it is found that these properties can be significantly improved by significantly affecting the amount of insoluble foreign substances and using a specific phosphorus compound.
The present invention has been reached. That is, according to the present invention, the object of the present invention belongs to the chlorophosphate-containing ester represented by the following formula [I] and groups I, II, VII and VIII in the 3rd and 4th periods of the periodic table. An aromatic polyester containing at least one metal compound selected from the group consisting of metal compounds, wherein the chlorophosphoric acid compound is contained in the polyester in an amount of 3 to 50 ppm as a phosphorus atom, and the metal compound is The following formula [I
It has been found to be achieved by an aromatic polyester composition characterized in that it is contained in the polyester in a proportion satisfying I].

[0010]

Embedded image

[In the formula, R ¹ , R ² and R ³ represent the same or different alkoxide group, allyloxide group, chloroalkoxide group or hydroxy group. However, R ¹ and R ²
At least one of R ³ and R ³ represents a chloroalkoxide group. ]

[0012]

[Chemical 4]

[In the formula, P represents the content ratio (mmol%) of the chlorophosphoric acid compound with respect to the dibasic acid component constituting the aromatic polyester, and M represents the metal with respect to the dibasic acid component constituting the aromatic polyester. The content rate (mmol%) of a compound is shown. The present invention will be described in more detail below.

The aromatic polyester in the present invention may be any polyester which is usually used as a material for fibers, films or molded articles. Specifically, a difunctional aromatic carboxylic acid is used as a main acid component, and an alkylene glycol is used. The main objects are polyesters containing as a main diol component. Examples of the difunctional aromatic carboxylic acid preferably used include terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, diphenylcarboxylic acid, diphenoxyethanedicarboxylic acid, β-hydroxyethoxybenzoic acid and p-oxybenzoic acid. Examples of the alkylene glycol include ethylene glycol, trimethylene glycol, tetramethylene glycol and the like. In particular, polyester containing ethylene terephthalate unit as the main repeating unit,
A polyester having a butylene terephthalate unit as a main repeating unit, a polyester having an ethylene naphthalate unit as a main repeating unit, or a polyester having a butylene naphthalate unit as a main repeating unit is preferable. The ethylene terephthalate unit, butylene terephthalate unit, ethylene naphthalate unit or butylene naphthalate unit is at least 8 in all repeating units.
Polyesters of 0 mol%, especially at least 90 mol%, are especially preferred.

Examples of the dibasic acid component which can be copolymerized with the polyester include isophthalic acid, 2,6-naphthalenedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, apicic acid and sebacic acid. The glycol component includes alkylene glycols such as 1,4-butanediol, neopentylene glycol, 1,4-cyclohexanediol and 1,4-cyclohexanedimethanol, and alicyclic compounds such as bisphenol A and bisphenol S. Mention may be made of group and aromatic diol compounds and polyoxyalkylene glycols.

Further, within a range in which the effects of the present invention are not substantially impaired, such as isophthalic acid, trimellitic acid, and pyromellitic acid having a sulfonate group such as 5-sodiumsulfoisophthalic acid in an aromatic polyester. Polycarboxylic acids, glycerin, trimethylolpropane, polyols such as pentaerythritol may be used as a copolymerization component. Such polyesters can be synthesized by any method. For example, polyethylene terephthalate is usually prepared by directly esterifying terephthalic acid and ethylene glycol, transesterifying a lower alkyl ester of terephthalic acid such as dimethyl terephthalate with ethylene glycol, or terephthalic acid and ethylene glycol. The reaction of the first step of reacting with oxide to produce a glycol ester of terephthalic acid and / or its low polymer and heating the reaction product of the first step under reduced pressure in the presence of a polymerization catalyst It is produced by a second stage reaction in which a polycondensation reaction is carried out until the degree of polymerization is reached.

The aromatic polyester of the present invention has an intrinsic viscosity [IV] of at least 0.45 dl / g, preferably at least 0.48 dl / g, and a terminal carboxyl group concentration of 15 eq / Ton or less, preferably 12 eq.
/ Ton or less is preferable because the effect of hydrolysis resistance is excellent. The aromatic polyester in the present invention contains, in the same manner as ordinary polyester, pigments such as titanium oxide and carbon black, as well as additives such as antioxidants, anti-coloring agents, light-resistant materials and antistatic agents. Good.
The composition of the present invention contains a chlorophosphate-containing ester represented by the following formula [I] in the aromatic polyester.

[0018]

Embedded image

In the above formula [I], R ¹ , R ² and R ³
Are the same or different alkoxide groups, allyloxide groups, chloroalkoxide groups or hydroxy groups.
However, at least one of R ¹ , R ² and R ³ represents a chloroalkoxide group.

R¹~ R³In the alkoxide group
Has 1 to 10 carbon atoms, preferably 2 to 5 carbon atoms.
A lucoxide group is desirable, and specifically -OCH₃, -O
C₂H _Five, -OC₃H₇, -OC_FourH₉And -OC_FiveH₁₁But
Can be mentioned. The aryloxyd has 6 to 12 carbon atoms.
Those of phenoxide (-O-C) are preferred.
₆H_Five) And toluroxide (-OC)₆H_Four-CH₃)
Is mentioned.

The phosphoric acid ester of the general formula [I] is R
^At least one of ^{1 to} R ³ is a chloroalkoxide group. The chloroalkoxide group is a group having 1 to 4 carbon atoms, preferably 1 to 3 carbon atoms, preferably 1 to 3 carbon atoms, to the alkoxide group having 1 to 10 carbon atoms, preferably 1 to 3 carbon atoms. In particular,

[0022]

[Chemical 6]

And the like. Conventionally, it has been known to use orthophosphoric acid, phosphorous acid, and their alkyl esters and allyl esters as stabilizers for aromatic polyesters. It is not clear why the chlorophosphate-containing ester of the formula [I] used in the present invention has an action of improving the hydrolysis resistance of the aromatic polyester as compared with these known stabilizers, but it is probably aromatic. The present inventors presume that the strength and weakness of the action of the phosphoric acid ester dispersed in the polyester as a hydrolysis catalyst is related. That is, it is considered that orthophosphoric acid and phosphorous acid have a considerably strong acidity, and when added in a large amount, they act as a strong hydrolysis catalyst like an aromatic polyester having a high terminal carboxyl group concentration.

On the other hand, in the chlorophosphate containing ester used in the present invention, the proton of the hydroxyl group is replaced by a specific organic group, and the acidity is extremely suppressed. By virtue of the fact that this specific organic group is a chloroalkoxide group, it disperses as fine particles in the aromatic polyester while maintaining a sufficient deactivating action of the transesterification catalyst or esterification catalyst, and acts as an extremely excellent stabilizer. It is considered to be a thing.

On the other hand, a lower trialkyl ester of phosphoric acid such as trimethyl phosphate is a compound having an apparently low acidity, but when exposed to the presence of hot ethylene glycol as a stabilizer, the phosphorus compound is converted into a strongly acidic compound. It has been confirmed that the effect of hydrolysis resistance is small. In addition, higher trialkyl esters of phosphoric acid and triphenyl esters of phosphoric acid that are less susceptible to thermal denaturation lose the effect of sufficiently deactivating transesterification catalysts and esterification catalysts, and have the effect of increasing the thermal stability of aromatic polyesters. poor.

It is the chloro-containing alkoxide group, the alkoxide group having a relatively large number of carbon atoms and the allyloxide group which are exposed to hot ethylene glycol so that the phosphorus compound is not easily converted into a strongly acidic compound. . Preferred as the chlorophosphate-containing ester of the present invention are R ¹ to
R ³ is a compound in which all are chloroalkoxide groups,
It is easy to synthesize and obtain. However, the phosphoric acid ester having a higher-grade organic group bonded thereto slows down the catalyst deactivation reaction rate and deteriorates heat resistance, and the size of foreign matter generated by the deactivation reaction of the catalyst and the phosphoric acid compound increases,
Further, the quality of the aromatic polyester is deteriorated, the synthesis of the phosphoric acid compound itself is difficult, it is difficult to obtain, and it is expensive, so that it is not practical to use.

In the present invention, the mixing ratio of the chlorophosphate-containing ester of the above formula [I] is based on the aromatic polyester.
It is in the range of 3 to 50 ppm, preferably 4 to 45 ppm in terms of the content of phosphorus (P) atoms. If it is less than this range, the effect of thermal stability is not achieved, and if it exceeds this range, the effect of hydrolysis resistance tends to be rather lowered. In the present invention, the amount of the phosphoric acid compound remaining in the aromatic polyester is an important point, but the chlorophosphoric acid ester having a heavy atomic weight chlorine in the molecule like the general formula [I] is a polyester. There is also an advantage that it does not easily scatter to the outside of the reaction system during the synthesis reaction and the residual amount is easily controlled.

The object of the present invention is achieved by containing the above-mentioned chlorophosphoric acid ester of the formula [I] in the aromatic polyester, but the specific content in the aromatic polyester is specified. By setting the content ratios of the metal and the phosphoric acid ester within the range satisfying the following formula [II], more excellent hydrolysis resistance and heat resistance can be obtained.

[0029]

[Chemical 7]

[In the formula, P represents the content ratio (mmol%) of the chlorophosphate-containing compound with respect to the dibasic acid component constituting the aromatic polyester, and M represents the metal with respect to the dibasic acid component constituting the aromatic polyester. The content rate (mmol%) of a compound is shown. The metal compound represented by M in the above formula [II] is used as a catalyst in the transesterification reaction between a dialkyl ester of an aromatic dicarbononic acid such as dimethyl terephthalate and a glycol in the production of an aromatic polyester. , And may be one kind or two or more kinds.

Examples of such transesterification catalysts include I, II, VII in the third and fourth periods of the periodic table.
And a compound of a metal belonging to Group VIII, and specific examples thereof include Na, K, Mg, Ca, and Mn.
And Co and the like. Of these, preferred are Mg, Ca, and Mn.

The chlorophosphate-containing ester of the above formula [I] used as a stabilizer for polyester reacts with M of the above metal catalyst to deactivate its transesterification action,
In addition, it is considered that the stability is improved and the potential of the polyester is increased by adding a small amount in the polyester by the direct esterification method which does not use such a catalyst. Therefore, the phosphate ester is converted into the amount of phosphorus ( P ) by at least 3 ppm, preferably at least 4 pp.
m is required. On the other hand, if it is not used for deactivating the catalyst ( M ) or is added in excess, the phosphate ester will act to some extent as a hydrolyzable catalyst,
The value of ( P − M ) in the formula [II] is 10 (mmol%).
It is suitable that the content is preferably 8 (mmol%) or less.

On the other hand, even in the case of the polyester produced by the direct ester method, if the metal catalyst ( M ) is intentionally added and adjusted so as to satisfy the value of the above formula [II], hydrolysis resistance and heat resistance are good. Makes polyester of excellent quality. Since the phosphoric acid ester of the present invention contains chlorine, it was feared that this would adversely affect toxicity and heat resistance, but the oral toxicity is at a level that is almost unchanged compared to orthophosphoric acid, and When added as stabilizers under the same conditions, polymerized polyester was spun under the same conditions, and the quality of the chips and the yarn was compared. Rather, it was recognized that the use of chlorophosphate-containing ester was suppressed.

According to the present invention described in detail above, there is provided a polyester which is excellent in hydrolysis resistance, thermal stability and color tone and has a small amount of insoluble foreign matters in the polyester. The reason for this has not been clarified yet, but it is speculated as follows. That is,
Transesterification catalyst added during polyester production,
And / or the polycondensation catalyst usually reacts with the phosphorus compound to form particles, but the phosphoric acid ester in the present invention has good dispersibility in the polyester, and since the deactivation reaction with the catalyst compound also has a suitable reactivity, This is probably because insoluble foreign matter is largely condensed and less likely to precipitate. In particular, in the chlorophosphate-containing ester of the present invention, at least one hydroxy group of orthophosphoric acid is substituted with a chloroalkoxide group, so that the activity as an acid catalyst is appropriately suppressed, so that the hydrolysis resistance of the polyester is improved. It is estimated that the heat resistance is improved and the color tone is improved.

Of course, in order to improve the hydrolysis resistance, it is important to reduce the concentration of the terminal carboxyl group as has been conventionally known. Therefore, the polyester polymerization process is optimized, and the high intrinsic viscosity by solid phase polymerization and A known low carbonation agent such as a low terminal carboxyl group concentration concentration, various epoxy compounds or carbodiimide compounds may be added by any method.

The aromatic polyester composition of the present invention is excellent in hydrolysis resistance, heat resistance and color tone, and has an extremely small amount of insoluble foreign matter of a large size, so that it can be molded and used in various fields. For example, a fiber formed from this composition is used not only for ordinary clothing applications but also for surgical clothing, uniforms, filtration filters and papermaking canvas applications for which hydrolysis resistance is particularly desired to be improved. It is used to advantage. Further, the composition of the present invention can be advantageously used for films and other molding materials.

[0037]

EXAMPLES The present invention will be described in more detail below with reference to examples. In addition, the part in an Example represents a weight part and each measured value followed the following method. (1) Intrinsic viscosity: The intrinsic viscosity [IV] of the polymer is 35
It was determined from the value measured with an ortho-chlorophenol solution at 0 ° C.

(2) Color tone: L value and b value representing the color tone of the polymer are values measured using a Hunter color difference meter,
The larger the L value, the higher the whiteness, and the larger the b value, the stronger the yellowness. That is, L
The larger the value and the smaller the b value, the better the color tone.

(3) Hydrolysis resistance and heat resistance: The hydrolysis resistance and heat resistance were evaluated as follows. Diameter 0.
An unstretched film obtained by spinning at a discharge rate of 80 g / min and a winding speed of 1,200 m / min using a spinneret having 30 3-mm spinning holes was drawn at a drawing temperature of 85 ° C and a draw ratio of 3.5 times. At a drawing speed of 1,100 m / min,
A 50 kg / 30 filament 25 kg roll was prepared. The heat resistance was judged from the changes in the intrinsic viscosity [IV] and [COOH] concentration before and after spinning. Meanwhile, the obtained yarn sample is
It was kept under moist heat at 60 ° C. for 60 hours, the yarn strength at that time was measured, and hydrolysis resistance was shown by the strength retention ratio relative to the untreated yarn. That is, it can be said that the higher the strength retention rate, the better the hydrolysis resistance.

(4) Amount of insoluble foreign matter : The amount of insoluble foreign matter was measured and evaluated as follows. After making the polymer into a thin film with a thickness of 10 μm, an optical microscope (× 200
The sample with a small amount of insoluble foreign matter observed under
Evaluation was made on a three-point scale, in which a sample with a relatively small amount was evaluated as Δ and a sample with a large amount was evaluated as ×.

Examples 1 to 4 and Comparative Examples 1 to 5 A mixture of 100 parts of dimethyl terephthalate, 64 parts of ethylene glycol, and manganese acetate was gradually heated to 230 ° C., and methanol was distilled off to cause a transesterification reaction. Add the chlorophosphoric acid compound shown in the following table,
After 5 minutes, antimony trioxide was added to obtain a low polymer. The types and addition amounts of manganese acetate and phosphorus compounds were added as shown in Table 1 when metal analysis of the polymer after polymerization was conducted by ICP. The obtained low polymer is heated to 265 ° C,
The polymerization reaction was started under reduced pressure. The polymerization reaction was carried out at 30 mmHg for 30 minutes, and at 1 mmHg or less in the next 30 minutes, the intrinsic viscosity [η] was increased to about 0.60 dl / g and the polymerization reaction was completed. The polymer obtained is 160
After drying at ℃ 4 hours, spinning temperature 290 ℃, winding speed 4
Spin at 00 m / min, then preheat 80 ° C, heat set 16
It was drawn 5 times at 0 ° C. to obtain a 24/40 de multifilament. Table 2 shows changes in intrinsic viscosity [η] in the spinning process, increase in terminal carboxyl group concentration, and hydrolysis resistance (strength retention rate).

[0042]

[Table 1]

[0043]

[Table 2]

[0044]

EFFECT OF THE INVENTION By adding a specific chlorophosphate-containing ester and, if necessary, specifying the catalyst species and the catalyst amount, it is possible to suppress the decrease in the intrinsic viscosity and the increase in the terminal carboxyl group concentration during molding or wet heat treatment. Provided are an aromatic polyester composition excellent in hydrolysis resistance and heat resistance, and having an extremely small amount of insoluble foreign matter, and a molded article made from the aromatic polyester composition.

Claims (3)

[Claims] 1. A compound selected from the group consisting of chlorophosphate-containing esters represented by the following formula [I] and compounds of metals belonging to groups I, II, VII, and VIII in the third and fourth periods of the periodic table. An aromatic polyester containing at least one metal compound, wherein the chlorophosphoric acid compound is contained in the polyester in an amount of 3 to 50 ppm as a phosphorus atom, and the metal compound has the following formula [I
The aromatic polyester composition is contained in the polyester in a ratio satisfying I]. Embedded image [In the formula, R ¹ , R ² and R ³ represent the same or different alkoxide groups, allyloxide groups, chloroalkoxide groups or hydroxy groups. However, at least one of R ¹ , R ² and R ³ represents a chloroalkoxide group. ] [Chemical 2] [In the formula, P is the content ratio of the chlorophosphoric acid compound to the dibasic acid component constituting the aromatic polyester (mmo
1%), M is the content ratio of the metal compound to the dibasic acid component constituting the aromatic polyester (mmol
%) Is shown. ] 2. Intrinsic viscosity [IV] of aromatic polyester
Is at least 0.45 dl / g, and the terminal carboxyl group concentration is 15 eq / T or less, The aromatic polyester composition according to claim 1. 3. A fiber formed from the aromatic polyester composition according to claim 1.