JP2011001453A - Method for producing polyester composition, and silica particle-alkylene glycol slurry - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a polyester composition in which silica particles are homogeneously dispersed with very little aggregation, and to provide alkylene glycol slurry containing silica particles, which is used in the method.SOLUTION: The method for producing a polyester composition comprises subjecting a reaction product, obtained by an esterification reaction or an ester exchange reaction of an aromatic dicarboxylic acid component and an alkylene glycol component, to a polycondensation reaction and adding silica particles in the state of alkylene glycol slurry in a period until the polycondensation reaction is finished. The silica particles have an average particle diameter of ≤1.5 μm and are added so that their amount becomes 0.001-5.0 wt.% based on the weight of the obtained polyester composition, and the alkylene glycol slurry is prepared to have a water content of 1.0-5.0 wt.%.

Description

  The present invention relates to a method for producing a polyester composition and a silica particle alkylene glycol slurry used therefor, and more particularly to a method for producing a polyester composition in which silica particles are uniformly dispersed.

  Aromatic polyesters represented by polyethylene terephthalate or polyethylene naphthalate have excellent physical and chemical properties, and are widely used in film applications such as magnetic tape, electrical insulation materials, capacitors, photographic films or packaging materials. Yes.

  When such a polyester is used for a film or the like, inert particles are added for the purpose of imparting excellent winding properties to the obtained film. Among such inert particles, the silica particles having a true spherical shape obtained by the alkoxide method or the water glass method have a sharp particle size distribution, so that it is easy to form protrusions uniformly on the film surface. It is used.

  By the way, the demand for films in recent years is becoming higher and higher, for example, higher surface flatness than before has been required. Particularly, agglomeration of locally generated silica particles, specifically, agglomeration between silica particles or between silica particles and a metal component added as a catalyst becomes a defect such as fish eye during film formation. Therefore, it has been desired for the polyester composition to uniformly disperse silica particles having a relatively small average particle diameter while suppressing aggregation.

  As a technique for suppressing aggregation of inert particles such as silica particles, for example, Patent Document 1 (Japanese Patent Application Laid-Open No. 7-216068) discloses a method of forming inert particles during a polyester polymerization reaction. Patent Document 2 (Japanese Patent Application Laid-Open No. 2003-238671) discloses a method of performing high-temperature pressure treatment at a temperature of 150 to 260 ° C. and a pressure of 0.05 to 0.3 MPa between the addition and the start of the polycondensation reaction. ) And a method of treating silica particles with a silane-based, titanate-based, or aluminum-based coupling agent has also been proposed in Patent Document 3 (Japanese Patent Laid-Open No. 63-31345). However, even with these methods, the aggregation suppressing effect is not sufficient, and further improvement has been desired.

  In order to suppress the aggregation of silica particles, a method using a titanium catalyst as a polymerization catalyst and using a phosphonate compound containing a carboxy group is proposed in Patent Document 4 (Japanese Patent Laid-Open No. 2005-239940). However, the silica particles specifically evaluated in Patent Document 4 are only relatively large particles having an average particle size of 2.0 μm or more, and are not sufficient as an aggregation suppressing effect of silica particles having a small average particle size.

Japanese Patent Laid-Open No. 7-21068 JP 2003-238671 A JP-A-63-312345 JP 2005-239940 A

  An object of the present invention is to solve the above-mentioned problems of the prior art, and to provide a method for producing a polyester composition capable of efficiently producing a polyester composition in which silica particles having a small average particle diameter are less agglomerated and are very uniformly dispersed. The object is to provide an alkylene glycol slurry of silica particles to be used.

  As a result of diligent research to solve the above-mentioned problems, the present inventor has drastically improved the dispersibility of silica particles by adding an ethylene glycol slurry containing silica particles of specific conditions, and locally generated silica. The present inventors have found that the large aggregation between particles is reduced and have reached the present invention.

Thus, according to the present invention, in the method for producing a polyester composition in which a reaction product obtained by esterifying or transesterifying an aromatic dicarboxylic acid component and an alkylene glycol component is subjected to a polycondensation reaction,
Until the completion of 80% of the esterification reaction or transesterification reaction, silica particles having an average particle size of 1.5 μm or less in the state of an alkylene glycol slurry, based on the weight of the polyester composition obtained, There is provided a method for producing a polyester composition comprising adding 001 to 5.0% by weight, and the alkylene glycol slurry having a moisture content in the range of 1.0 to 5.0% by weight. The

  Further, according to the present invention, as a preferred embodiment of the present invention, a polyester composition comprising at least one of the esterification reaction or the transesterification reaction being performed in the presence of a titanium compound or via the transesterification reaction. A method of manufacturing the article is also provided.

  Furthermore, according to this invention, it is the alkylene glycol slurry containing a silica particle, Comprising: The alkylene glycol slurry for polyester compositions which has a moisture content in the range of 1.0 to 5.0 weight% is also provided.

  According to the present invention, the moisture content in the alkylene glycol slurry containing silica particles is adjusted to a specific range, so that the silica particles can be uniformly dispersed in the polyester composition without agglomeration. Therefore, it is possible to produce a polyester composition that can be suitably used as a raw material such as a film that requires extremely flat surface properties.

  Before describing the method for producing the polyester composition of the present invention, another alkylene glycol slurry of silica particles according to the present invention will be described.

  The alkylene glycol slurry of the present invention is an alkylene glycol slurry containing silica particles used for producing a polyester composition, and the water content in the slurry is in the range of 1.0 to 5.0% by weight. A preferable moisture content is in the range of 1.5 to 4.5% by weight, particularly in the range of 2.0 to 4.0% by weight. By adjusting the moisture content in the alkylene glycol slurry within the above range, it is possible to prevent large aggregation of silica particles locally generated in the resulting polyester composition. The reason for this is presumably because the reaction between silanol groups remaining in the silica particles is inhibited by moisture, and aggregation of silica after addition to the production process of the polyester composition is suppressed. Similarly, it is presumed that the moisture also suppresses aggregation caused by the reaction between the catalyst and the silica particles. Therefore, when the moisture content in the alkylene glycol slurry is less than the above lower limit, the effect of suppressing the aggregation of the silica particles is hardly exhibited. From such a viewpoint, it seems that the higher the moisture content, the better. However, if the moisture content exceeds the above upper limit, the silica particles themselves are hydrolyzed and silanol groups are generated, or rather agglomeration is more likely. Become.

  By the way, the concentration of the silica particles in the alkylene glycol slurry is 2 to 25% by weight based on the weight of the slurry, from the viewpoint of suppressing the dispersion stability of the silica particles and the generation of by-products in the production process of the polyester composition. The range is preferable, and the range of 5 to 20% by weight is more preferable. Moreover, it is preferable that the alkylene glycol slurry of silica particles is subjected to a heat treatment in advance before preparing the moisture content described above, and the silanol groups remaining in the silica particles are reduced by reaction with alkylene glycol. The heat treatment temperature is preferably in the range of 120 to 230 ° C, and more preferably in the range of 150 to 195 ° C. The heat treatment time may be appropriately adjusted depending on the heating temperature, but it is preferably 60 minutes or more from the viewpoint of sufficient treatment. On the other hand, the upper limit of the heat treatment time is not particularly limited, but it is preferably 5 hours or less from the viewpoint of suppressing production of by-products such as dialkylene glycol due to productivity and heating.

Further, the silica particles used in the present invention are silica particles having an average particle size of 1.5 μm or less. A preferable average particle diameter is 1.0 μm or less, and further 0.5 μm or less. The lower limit of the average particle diameter of the silica particles is not particularly limited, but is preferably 0.01 μm or more from the viewpoint of handleability. Moreover, it is preferable that the shape of a silica particle is a spherical shape. The true spherical shape in the present invention is, for example, by taking a photograph of each particle at a magnification according to the size of the silica particles used by a scanning electron microscope, using an image analysis processor Luzex 500 (manufactured by Japan Regulator Co., Ltd.), The projection surface maximum diameter (D) (μm) and the area circular equivalent diameter of the projection surface are measured, and the particle volume (V) (μm ³ ) calculated as a sphere from the area circular equivalent diameter and the above-mentioned maximum projection surface diameter. From (D) (μm), the volume spherical coefficient (f) was calculated. The volume spherical coefficient (f) is obtained by dividing the V in D ^3. The true spherical particle in the present invention means a particle having f of 0.4 to π / 6. In addition, since the silica particles in the present invention are preferably particles having a spherical shape that can easily form protrusions having a relatively uniform protrusion height when formed into a film, the average value (D _L ) of the major axis of the silica particles is determined. The particle size ratio (D _L / D _S ) divided by the average value (D _S ) of the minor axis of the silica particles is preferably in the range of 1.0 to 1.2. Further, spherical silica particles preferably used is preferably one less coarse particles contained in the inert particles themselves, the particle size of the particle diameter of cumulative particle number of 70% of (D ₇₀₎ cumulative particle number 30% (D ₃₀ ) (D70 / D30) is preferably in the range of 1.1 to 2.0, more preferably 1.2 to 1.5.

  The alkylene glycol slurry of silica particles of the present invention is filtered with a filter for the purpose of removing aggregated particles and slightly contained coarse particles contained in the alkylene glycol slurry before being added to the polyester composition. It is preferable to do. The aperture of the filter used is determined by the particle size of the silica particles.

  Below, the manufacturing method of the polyester composition which is another this invention is demonstrated. The method for producing a polyester composition of the present invention comprises a polycondensation reaction of a reaction product obtained by an esterification reaction or an ester exchange reaction of an aromatic dicarboxylic acid component and an alkylene glycol component, and an esterification reaction or an ester. The above-described alkylene glycol slurry of the present invention is added until the exchange reaction proceeds by 80% or more.

  The production method of the polyester composition of the present invention is such that the addition amount of silica particles is 0.001 to 5.0% by weight based on the weight of the polyester composition obtained from the above-described alkylene glycol slurry of the present invention. To be added. A preferable range of the addition amount is 0.01 to 2.5% by weight, and further 0.05 to 1.0% by weight. When the addition amount of the silica particles is less than the lower limit, the effect of improving the slipperiness due to the addition of the silica particles tends to be poor, and when the addition amount exceeds the upper limit, the aggregation of the silica particles increases.

  The polyester in the present invention is preferably a polyester composed of a dicarboxylic acid component and an alkylene glycol component, and is not particularly limited as long as it has film-forming properties on a film or the like. Among such polyesters, polyesters in which 80 mol% or more, particularly 85 mol% or more of all repeating units are composed of ethylene terephthalate units or ethylene-2,6-naphthalate units are preferable from the viewpoint of mechanical properties. From such a viewpoint, the alkylene glycol slurry in the present invention is preferably an alkylene glycol slurry having 2 to 4 carbon atoms, and particularly preferably an ethylene glycol slurry. Of course, within the range not impairing the effect of the present invention, for example, the other third component is copolymerized at 20 mol% or less, further 15 mol% or less, particularly 10 mol% or less, with respect to all repeating units of the aromatic polyester. It may be a copolymer. The third component (copolymerization component) includes terephthalic acid (in the case of ethylene-2,6-naphthalate unit), 2,6-naphthalenedicarboxylic acid (in the case of ethylene terephthalate unit), 2,7-naphthalenedicarboxylic acid, isophthalic acid , Aromatic dicarboxylic acids such as phthalic acid, aliphatic dicarboxylic acids such as adipic acid, azelaic acid, sebacic acid and decanedicarboxylic acid, alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid, trimethylene glycol, diethylene glycol, tetramethylene Glycols such as glycol and cyclohexanedimethanol can be exemplified, and these may be used alone or in combination of two or more.

  The method for producing the polyester composition of the present invention is a melt polymerization method in which a low polymer obtained therefrom is subjected to a polycondensation reaction via an esterification reaction or a transesterification reaction. In addition, although it may pass through either esterification reaction or transesterification reaction, since it is easy to control the water content during reaction, it is preferable to go through transesterification reaction.

  In the production method of the present invention, the esterification reaction and the transesterification reaction may be performed in the presence of a catalyst. As the catalyst to be present, a titanium compound that can be relatively reduced in addition to the fact that it is easy to flatten the surface of the resulting molded product when formed into a film or the like, and that there is little decrease in the reaction rate due to the presence of water. preferable. Moreover, dispersion | distribution of the silica particle in a polyester composition can be improved more by using a titanium compound.

By the way, as the titanium compound used in the present invention, an organic titanium compound that is soluble in polyester is preferable, and since the excellent heat resistance can be imparted to the polyester composition obtained and a film obtained by molding it, the following general formula ( I)
Ti (OR ¹ ) (OR ² ) (OR ³ ) OR ⁴ (I)
(In formula (I), R ¹ , R ² , R ³ and R ⁴ represent an alkyl group having 1 to 10 carbon atoms or a phenyl group.)
Or a compound represented by the above general formula (I) and the following general formula (II)
C ₆ H _6-n (COOH) _n (II)
(In formula (II), n is an integer of 2 to 4.)
A reaction product with an aromatic polyvalent carboxylic acid represented by or an anhydride thereof is desirable.

  Specific examples of the titanium compound represented by the general formula (I) include titanium tetraisopropoxide, titanium tetrapropoxide, titanium tetrabutoxide, titanium tetraethoxide, titanium tetraphenoxide and the like. On the other hand, the aromatic polyvalent carboxylic acid represented by the general formula (II) or the anhydride thereof reacted with the titanium compound of the general formula (I) includes phthalic acid, trimellitic acid, hemimellitic acid, pyromellitic. Preferred examples include acids and anhydrides thereof.

  In order to react the titanium compound of the above general formula (I) with the aromatic polyvalent carboxylic acid of the above general formula (II) or an anhydride thereof, one solvent of the aromatic polyvalent carboxylic acid or the anhydride thereof is used as a solvent. A part is melt | dissolved, a titanium compound may be dripped at this, and what is necessary is just to react for 30 minutes or more at the temperature of 0-200 degreeC.

  The amount of the titanium compound to be added is not particularly specified, but is preferably in the range of 2 to 30 mmol%, particularly in the range of 3 to 15 mmol%, in terms of titanium element, based on the total dicarboxylic acid component of the polyester. It is preferable. When the amount of the titanium compound is less than 2 mmol%, the effect of improving the reaction rate due to the titanium compound becomes poor. On the other hand, when the amount of the titanium compound exceeds 50 mmol%, the thermal decomposition reaction proceeds simultaneously during the polycondensation reaction. It becomes easy and it becomes difficult to raise a polymerization degree, or thermal stability deteriorates. In addition, when adding a titanium compound, it is added so that it may exist from the time of esterification reaction or transesterification start, and it is preferable to use it continuously as a polycondensation reaction catalyst as mentioned above. Of course, it may be added in two or more times for the purpose of controlling the polycondensation reaction rate.

  By the way, in the production method of the present invention, the addition time of the alkylene glycol slurry containing the silica particles needs to be added at an earlier stage in order to improve the dispersibility of the silica particles, and the esterification reaction or transesterification is required. In the reaction, the polyester precursor is preferably added until the esterification reaction rate or transesterification reaction rate reaches 80%. When added after the esterification reaction rate or transesterification reaction rate is equal to or higher than the above value, the dispersion state of the silica particles in the polyester composition is deteriorated, and large aggregation tends to occur. The esterification reaction rate and the transesterification reaction rate can be grasped by, for example, the ratio of the amount of generated methanol and the total amount of methanol generated when methanol is generated by the transesterification reaction. Preferably, it is added so that it exists from the beginning of the esterification reaction or transesterification reaction.

  In the production method of the present invention, it is preferable to add a phosphorus compound as a heat stabilizer between the end of the esterification reaction or the transesterification reaction and the start of the polycondensation reaction. The type of phosphorus compound to be used is not particularly limited and known ones can be used, but it is preferable to add a phosphonate compound represented by the following formula (III). Dispersibility can be further increased by adding the phosphonate compound represented by (III). Examples of particularly preferred phosphonate compounds represented by (III) include ethyl diethoxyphosphonoacetate and methyl diethoxyphosphonoacetate.

（式III中、Ｒ^５およびＲ^６は、それぞれ炭素数が１〜４のアルキル基であり、Ｘは−（ＣＨ_２）ｍ−又は−ＣＨ（Ｙ）−（ｍは０以上４以下の整数、Ｙはフェニル基）を表す。）

(In Formula III, R ⁵ and R ⁶ are each an alkyl group having 1 to 4 carbon atoms, and X is — (CH ₂ ) m — or —CH (Y) — (m is an integer of 0 or more and 4 or less. , Y represents a phenyl group).

The addition amount of the phosphorus compound in the present invention varies depending on the difference in the transesterification reaction or esterification reaction and the addition amount of the titanium compound catalyst to be used, but satisfies the following relationship based on the amount of the titanium compound catalyst to be used. It is preferable to do.
0.5 ≦ P / Ti ≦ 3.0
(P and Ti in the above formula are respectively the mol% in terms of phosphorus element of the phosphorus compound and the mol% in terms of titanium element of the titanium compound, based on the number of moles of all repeating units of the polyester.) By setting it within such a range, the dispersibility of the silica particles can be enhanced while maintaining the polycondensation reactivity and the obtained polyester composition.

  By the way, as the addition method of this phosphonate compound, since it is easy to suppress aggregation of a silica particle, adding in the state of an alkylene glycol solution is preferable. The concentration of the phosphorus compound in the alkylene glycol solution is not particularly specified, but it is preferably as low as possible from the viewpoint of suppressing aggregation. However, when the concentration is excessively low, alkylene glycol is excessively added, and there is a problem that the amount of diethylene glycol in the polyester composition is increased, 0.5 to 30% by weight, and further 1 to 20% by weight It is preferable to add in a range. In addition, you may perform addition at once and may divide | segment into 2 times or more.

  Thus, after adding a phosphorus compound, a polycondensation reaction is performed until it becomes the desired intrinsic viscosity. The polycondensation reaction catalyst to be used is not particularly limited, but it is preferable to use a titanium compound as the polycondensation reaction catalyst as described above. Of course, solid phase polymerization or the like may be performed as necessary. In addition, the intrinsic viscosity of the obtained polyester composition is preferably 0.40 dl / g or more, more preferably in the range of 0.45 to 1.0 dl / g, from the viewpoint of strength and abrasion resistance when used as a film. It is preferable that

  As described above, by using the slurry and the production method of the present invention described above, it is possible to improve the dispersibility of the silica particles in the polyester composition, and to produce a polyester composition in which the silica particles are uniformly dispersed without agglomeration. Can do.

  The present invention will be specifically described below with reference to examples. In addition, the characteristic of the polyester composition in this invention was measured and evaluated by the following method.

(1) Intrinsic viscosity (IV)
A polymer sample was dissolved in orthochlorophenol at a temperature of 35 ° C. and measured.

(2) Dispersion rate of silica single particles A film sample is subjected to ion etching treatment on the film surface under the following conditions using a sputtering apparatus (1B-2 type ion coater apparatus) manufactured by Eiko Engineering Co., Ltd. The condition is that a sample is placed in a cylinder jar, the degree of vacuum is increased to a vacuum state of about 6.65 Pa, and ion etching is performed at a voltage of 0.45 kV and a current of 5 mA for about 15 minutes. Furthermore, gold sputtering was performed on the film surface with the same apparatus. Then, using a scanning electron microscope (Hitachi S-2150), the total number of primary particles and the number of aggregated particles in the range of 1 × 10 ⁻² mm ^{2 at} a measurement magnification of 5,000 to 20,000 times were counted, and Obtained from the equation. Here, the aggregate of two or more silica particles is an aggregated particle. When two primary particles are formed, the number of aggregated particles is two, and when the three primary particles are formed, the number of aggregated particles is Counted as three.
Aggregated particle ratio (%) = number of aggregated particles ÷ total number of primary particles × 100

(3) Large aggregation number of silica particles After film samples were ion-etched and gold-sputtered in the same manner as in (2), 10 or more primary particles were measured at a scanning magnification of 2,000 to 10,000 with a scanning electron microscope. Aggregating large aggregates were counted in the range of 1 mm ² . The number of large aggregates was counted not as the number of individual primary particles forming the aggregate but as the number of aggregates.

(4) Measurement of moisture content A trace amount of silica alkylene glycol slurry was measured for moisture content with a moisture measuring device (AQ-3C) manufactured by Hiranuma Sangyo Co., Ltd., and the moisture content was calculated.

[Example 1]
Ethylene glycol is added with spherical silica particles having an average particle size of 0.1 μm and a volume spherical coefficient of 0.52 and water, and the silica particle content is 10% by weight based on the weight of the slurry. A silica particle-containing ethylene glycol slurry having a moisture content of 2.5% by weight was prepared.
Next, 100 mol of 2,6-naphthalenedimethyl ester (NDCM) and 200 mol of ethylene glycol (EG) were charged into a transesterification reaction vessel, and the temperature was raised to 170 ° C. Then, 0.008 mol of trimellitic acid titanium, which is a compound obtained by reacting tetrabutoxy titanium and trimellitic acid in a molar ratio of 1: 2, is added, and the silica particle-containing ethylene glycol slurry is based on the weight of the polyester obtained. The silica particles were added so that the content of silica particles was 0.3% by weight.
Thereafter, the entire transesterification tank was pressurized to 0.10 MPa to carry out the transesterification reaction. After the internal temperature of the transesterification reaction tank reached 235 ° C., the pressure was released, 0.015 mol of 10 wt% ethylene glycol solution of ethyl diethoxyphosphonoacetate was added in phosphorus amount, and the temperature was raised to 245 ° C. The obtained reaction product is transferred to a polymerization reaction tank, the pressure in the polycondensation reaction tank is slowly reduced while the temperature is raised, and finally polycondensation is performed under a polycondensation temperature of 300 ° C. and a vacuum of 100 Pa. A polyester composition having an intrinsic viscosity of 0.62 dl / g was obtained.

  The polyester composition thus obtained was dried at 180 ° C. for 4 hours, then melted at 290 ° C., and the molten polyethylene-2,6-naphthalate resin composition was extruded onto a rotating casting drum. An unstretched sheet having a thickness of 350 μm was obtained. Next, this unstretched sheet was simultaneously biaxially stretched by 3.75 times in the longitudinal direction and the width direction at 150 ° C. with a biaxial stretching apparatus to prepare a film sample having a thickness of 25 μm. The properties of the obtained polyester composition are shown in Table 1.

[Examples 2 to 5, Comparative Examples 1 to 3]
As shown in Table 1, the same operation as in Example 1 was repeated except that the particle size of the silica particles, the moisture content in the slurry, the addition amount, and the addition time were changed. The properties of the obtained polyester composition are shown in Table 1.

  According to the present invention, it is possible to uniformly disperse silica particles having a small average particle diameter that easily cause aggregation in the polyester composition, and when used in a film, it is possible to obtain a film having extremely excellent surface flatness. For example, it can be suitably used for a base film of a magnetic recording medium.

Claims (4)

In the method for producing a polyester composition in which a reaction product obtained by esterifying or transesterifying an aromatic dicarboxylic acid component and an alkylene glycol component is subjected to a polycondensation reaction,
Until the completion of 80% of the esterification reaction or transesterification reaction, silica particles having an average particle size of 1.5 μm or less in the state of an alkylene glycol slurry, based on the weight of the polyester composition obtained, A method for producing a polyester composition, characterized in that the addition is made to be 001 to 5.0% by weight, and the alkylene glycol slurry has a moisture content in the range of 1.0 to 5.0% by weight.   The method for producing a polyester composition according to claim 1, wherein the esterification reaction or transesterification reaction is carried out in the presence of a titanium compound.   The manufacturing method of the polyester composition of Claim 1 which passes through transesterification.   An alkylene glycol slurry containing silica particles, wherein the moisture content is in the range of 1.0 to 5.0% by weight.