JP2010265406A - Polyester composition, film using the same and method for preparing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyester composition having extremely small internal haze, and a polyester film having extremely small internal haze using the same. <P>SOLUTION: The polyester composition is obtained by using a particular phosphonate compound as a deactivator for a polymerization reaction in an amount corresponding to 15-120 mmol% in terms of phosphorus element based on the total mole of acid components in the polyester. The polyester composition comprises <0.1 wt.% externally added particles having an average particle size of ≥0.05 μm. The film is formed using the same. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a polyester composition and a method for producing the same, and more particularly to a polyester composition suitable for forming a sheet or film having a small internal haze and a method for producing the same.

  Polyesters typified by polyethylene terephthalate or polyethylene naphthalate have excellent physical and chemical properties, and are widely used for film applications such as magnetic tapes, electrical insulating materials, capacitors, photographic films or packaging materials. Especially in recent years, it has been widely used in various optical films, and is used in applications such as prism lens sheets for liquid crystal display device members, base films such as touch panels and backlights, base films for anti-reflection films, and base films for explosion-proof displays. It is used.

  By the way, the demand for films in recent years has become increasingly high, and in particular, reduction of internal haze has been required. One way to reduce this internal haze is to not add inert particles that are added to improve the handling of the film.・ It is also necessary to improve the aggregation.

  From such a viewpoint, Japanese Patent Application Laid-Open No. 2004-210873 (Patent Document 1) proposes to use two types of phosphorus compounds. However, it was still insufficient as an internal haze.

  On the other hand, regardless of the internal haze, Japanese Patent Application Laid-Open No. 2008-24746 (Patent Document 2) requires a specific phosphorus compound from the viewpoint of suppressing aggregation of externally added particles to be contained in order to improve the handleability of the film. Has been proposed. Japanese Patent Laid-Open No. 2007-182470 (Patent Document 3) proposes to use the phosphorus compound proposed in Patent Document 2 from the viewpoint of imparting flame retardancy to the film.

JP 2004-210873 A JP 2008-24746 A JP 2007-182470 A

  An object of the present invention is to solve the problems of the prior art and provide a polyester composition having an extremely low internal haze and a polyester film having an extremely low internal haze using the same.

  As a result of diligent research to solve the above-mentioned problems, the present inventors have surprisingly found that when the phosphorus compound proposed in Patent Documents 2 and 3 is used as a deactivator for the polymerization reaction in the polyester polymerization process. The present inventors have found that the internal haze can be reduced and have reached the present invention.

（式中、Ｒ^１およびＲ^２は、それぞれ炭素数２以上のアルキレン基であり、ｍおよびｎは正の整数で、ｍ＋ｎは３〜１０の範囲である。）で示されるホスホネート化合物を、重合反応の失活剤として、ポリエステルの全酸成分のモル数を基準として、リン元素量で１５〜１２０ｍｍｏｌ％の範囲で用いたポリエステル組成物であって、かつ平均粒径が０．０５μｍ以上の外部添加粒子の含有量が０．１重量％未満であるポリエステル組成物及びそれを用いたポリエステルフィルムが提供される。 Thus, according to the present invention, the following structural formula (I)

(Wherein R ¹ and R ² are each an alkylene group having 2 or more carbon atoms, m and n are positive integers, and m + n is in the range of 3 to 10). A polyester composition used as a reaction quencher in the range of 15 to 120 mmol% in terms of phosphorus element amount based on the number of moles of all acid components of the polyester, and having an average particle size of 0.05 μm or more A polyester composition having a content of additive particles of less than 0.1% by weight and a polyester film using the same are provided.

  Further, according to the present invention, as a preferred embodiment of the present invention, the external additive particles are not added, and the Sb compound is in the range of 80 to 200 ppm in terms of the amount of Sb element based on the weight of the polyester composition obtained. And a polyester composition further comprising at least one of the above-mentioned doors in which the polyester is polyethylene terephthalate or polyethylene-2,6-naphthalenedicarboxylate, and a polyester film using the same.

  Furthermore, according to the present invention, the polyester is polymerized without adding externally added particles having an average particle size of 0.05 μm or more at a ratio of 0.1% by weight or more based on the weight of the obtained polyester composition. Of the polyester composition in which the phosphonate compound represented by the structural formula (I) is added to the process so as to be in the range of 15 to 120 mmol% in terms of the amount of phosphorus element with respect to the total acid component of the obtained polyester. A manufacturing method is also provided.

  According to the present invention, a polyester composition having an extremely low internal haze is produced by using the phosphonate compound represented by the above formula (I) as a quenching agent for the polymerization reaction and not using externally added particles that increase the internal haze as much as possible. it can. Therefore, if a film is produced using the polyester composition of the present invention, a highly transparent film can be produced, and its industrial value is extremely high.

  The polyester in the present invention is preferably a polyester comprising an aromatic dicarboxylic acid component and an ethylene glycol component, and particularly preferably has film-forming properties on a film or the like. Among such polyesters, polyesters in which 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. Of course, a copolymer obtained by copolymerizing the other third component within a range not impairing the effects of the present invention, for example, 15 mol% or less, preferably 10 mol% or less, with respect to all repeating units of the aromatic polyester. It may be. As the third component (copolymerization component), 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 polyester composition of the present invention needs to use the phosphonate compound represented by the structural formula (I) in the polymerization reaction. Such a phosphonate compound is used as a deactivator for a polymerization reaction, and transparency can be improved by using it in a specific range as a deactivator for a polymerization reaction.

R ¹ and R ² of the phosphonate compound represented by the general formula (I) are alkylene groups having 2 or more carbon atoms, and may be linear or branched. The alkylene group is an alkylene group having 2 to 18 carbon atoms, preferably 2 to 8 carbon atoms. Specifically, an ethylene group, a propylene group, a butylene group, an isopropylene group, a t-butylene group, a sec-butylene group, etc. Can be illustrated. The cycloalkylene group is a cycloalkylene group having 3 to 18 carbon atoms, preferably 3 to 8 carbon atoms. Specific examples include a cyclobutylene group, a cyclopentylene group, and a cyclohexylene group. Can do. In the formula, R ¹ and R ² may be the same group or different groups.

  In the general formula (I), m and n are positive integers which may be the same or different from each other, and the range of m + n is 3 to 10. When m + n is less than the lower limit, the phosphonate compound itself is easily hydrolyzed, and when it exceeds the upper limit, the phosphonate compound itself is easily pyrolyzed. A preferable range of m + n is 4 to 8, particularly 4 to 7.

  Specific examples of the phosphonate compound represented by the general formula (I) include compounds as listed in Table 1 below.

  The addition amount of the phosphonate compound represented by the general formula (I) is in the range of 15 to 120 mmol%, preferably 20 to 60 mmol%, particularly preferably, in terms of the amount of phosphorus element, with respect to the total acid component of the polyester obtained It is the range of 25-50 mmol%. When this addition amount is less than the lower limit, the resulting polyester resin composition has poor heat resistance, and when it exceeds the upper limit, transparency tends to decrease. In the present invention, the phosphonate compound described above is not limited to one type, and two or more types may be used in combination. Moreover, the phosphonate compound shown by the said general formula (I) can be manufactured by a well-known method, for example, can be obtained by esterifying a desired diol with hydroxymethyl phosphoric acid.

  The reason why such a phosphorus compound has transparency is unclear, but originally, a metal compound contained as a catalyst or an impurity and a phosphorus compound are bonded and precipitated as a foreign substance in the polyester resin, but used in the present invention. It is considered that the specific phosphonate compound easily dissolves the foreign matter in the polyester resin. For this reason, it is preferable that all phosphorus compounds used as a quencher for the polymerization reaction are phosphonate compounds of the above general formula (I).

  In the present invention, from the viewpoint of suppressing internal haze, it is preferable that the externally added particles for improving the slipperiness by making the surface of the film uneven are not contained as much as possible. From such a viewpoint, the content of the externally added particles having an average particle size of 0.05 μm or less needs to be less than 0.1% by weight based on the weight of the obtained polyester composition. The content of the externally added particles is preferably less than 0.05% by weight, more preferably less than 0.01% by weight. The externally added particles in the present invention mean particles added from the outside in order to improve the slipperiness by making the film surface uneven. On the other hand, there are other particles such as internal precipitation particles formed by positively depositing a catalyst or the like and insoluble foreign substances brought from raw materials, but it is obvious that these are preferably as small as possible.

If the polyester composition of the present invention has an intrinsic viscosity (measured at a temperature of 35 ° C. using an o-chlorophenol solvent) that is too small, mechanical properties may be insufficient. Therefore, it is preferably in the range of 0.40 to 0.90 dl / g.
It should be noted that various known additives such as an antistatic agent, an antioxidant, an ultraviolet absorber, and a lubricant filler may be contained within a range not impairing the object of the present invention.

  Next, another method for producing a polyester composition according to the present invention will be described. 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 a transesterification method or a direct esterification method. In addition, as a catalyst used in these reactions, a catalyst known per se can be used. For example, as the transesterification catalyst, compounds such as manganese, cobalt, zinc, titanium, calcium, etc., as the esterification catalyst, compounds such as manganese, cobalt, zinc, titanium, calcium, etc., as the polycondensation catalyst, germanium, Examples include compounds such as antimony, tin, titanium, and aluminum. In particular, antimony compounds are used as polycondensation catalysts. It is preferable when improving the heat resistance of the obtained polyester composition. When an antimony compound is used as the polycondensation catalyst, the amount of antimony is in the range of 80 to 200 ppm, more preferably in the range of 90 to 180 ppm, particularly 100 to 160 ppm, based on the weight of the polyester composition. From the viewpoint of providing high heat resistance and high degree. When the addition amount of the antimony compound is less than the lower limit, it is difficult to sufficiently proceed the polymerization reaction with the antimony compound alone, and when it exceeds the upper limit, many foreign matters derived from the catalyst are often found in the polyester composition. And the internal haze tends to be high.

  In the present invention, it is necessary to add the phosphonate compound represented by the general formula (I) as a quenching agent for the polymerization reaction, and the addition time is not particularly limited as long as it is during the polymerization process of the polyester, The polyester is preferably added after the ester exchange reaction or esterification reaction and before the polycondensation reaction.

  The polyester resin thus obtained can be once molded into a pellet and then melted again or continuously into various molded articles without being molded into a pellet. Further, if necessary, further polymerization may be performed until a desired intrinsic viscosity is obtained by solid phase polymerization. As a molding method, for example, it can be molded into an arbitrary shape such as a plate shape, a sheet shape, a film shape, a thread shape by extrusion molding, injection molding, blow molding, foam molding, spinning molding, film forming, etc. In particular, since the internal haze is extremely small, it can be suitably used for a film. The obtained molded product can be used in various fields such as industrial equipment, automobiles / vehicles, electric / electronic parts and the like.

  The molding machine used in these moldings is not particularly limited. For example, an ordinary injection molding machine, a so-called injection compression molding machine, a twin screw extruder, a single screw extruder, a twin screw extruder with a vent, or a vent. A single screw extruder or the like is preferably used.

Furthermore, the method of using the polyester resin composition of the present invention as a polyester film will be further described by taking a biaxially stretched film as an example.
First, the polyester composition of the present invention (after drying in the case of pellets), for example, extruded at a melting temperature of 260 ° C. to 310 ° C. through a die through a die, cast onto a cooling drum, and cooled and solidified. To create an unstretched film. This unstretched film is stretched in the longitudinal direction at a temperature of 60 to 140 ° C. at a magnification of 3 to 8 times, and then stretched in the transverse direction at a temperature of 70 to 180 ° C. at a magnification of 3 to 7 times to give a biaxially oriented polyester A film can be obtained. If necessary, longitudinal and / or transverse stretching may be divided into two or more stages (longitudinal multi-stage stretching, longitudinal-horizontal-vertical three-stage stretching, longitudinal-horizontal-vertical-horizontal 4). Step stretching, etc.). Moreover, you may implement by simultaneous biaxial stretching. The total draw ratio when producing the biaxially oriented polyester film is preferably 10 to 35 times, more preferably 12 to 30 times as the area draw ratio. Further, the biaxially oriented polyester film is preferably heat-set at a temperature of 140 to 250 ° C. after biaxial stretching, particularly preferably 180 to 230 ° C. The heat setting time is preferably 1 to 60 seconds. In addition, the polyester film of this invention may add another polyester resin composition, a functional agent, etc. in the range which does not impair the effect of this invention, and provides a well-known functional layer on the surface. Also good.

  The polyester film of the present invention thus obtained has a low internal haze and is excellent in heat resistance, so that it can be suitably used for applications requiring various transparency and heat resistance.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further more concretely, this invention is not limited by these Examples. In addition, the various characteristics in this invention followed the following measuring methods.

(1) Intrinsic viscosity Using o-chlorophenol as a solvent, the viscosity was measured using an Ostwald viscometer under a constant temperature in an atmosphere of 35 ° C.

(2) Internal haze The polyester composition pellets were dried at 160 ° C. for 2 hours, melt-extruded into a sheet at 290 ° C., and then solidified on a rotary cooling drum having a surface temperature of 30 ° C. to obtain an unstretched film. This unstretched film is stretched 3.5 times in the longitudinal direction and 3.5 times in the transverse direction at 120 ° C. and heat-set at 180 ° C. to produce a biaxially stretched film having a thickness of 50 μm.
The obtained biaxially stretched polyester film was measured according to JIS K7361 using a haze measuring device (trade name “NDH-2000” manufactured by Nippon Denshoku Industries Co., Ltd.).
The total light transmittance (%) and the scattered light transmittance (%) were determined for any three points of the biaxially stretched polyester film. The average values of these three points were taken as the total light transmittance Tt (%) and the scattered light transmittance Td (%), respectively. From these numerical values, haze (Td / Tt × 100 (%)) was calculated.

(3) Phosphorus content in polymer A polymer sample was heated and melted to prepare a circular disk, which was measured using a Rigaku fluorescent X-ray apparatus 3270 type, and quantified.

(4) Measurement of element amount of antimony compound A polymer sample was heated and melted to prepare a circular disk, which was measured using a Rigaku fluorescent X-ray apparatus 3270 type and quantified.

(5) Average particle diameter From the cumulative particle size distribution measured using a laser scattering particle size distribution analyzer (SALD2000 manufactured by Shimadzu Corporation), the average particle diameter was 50% of the cumulative particle number (volume conversion).

(6) Evaluation of heat resistance of polymer The intrinsic viscosity after the polymer sample was heat-treated at 175 ° C. for 24 hours was measured, and the heat resistance was evaluated from the difference (ΔIV) from the intrinsic viscosity before the heat treatment.

[Example 1]
100 mol of dimethyl terephthalate (DMT), 200 mol of ethylene glycol (EG) and 0.03 mol of manganese acetate tetrahydrate were charged into a transesterification reactor, and the temperature was raised to 190 ° C. Thereafter, methanol was removed while raising the temperature to 240 ° C. to complete the transesterification reaction.
Subsequently, a 10 wt% ethylene glycol solution of 0.01 mol of diantimony trioxide and dioxyethylene trioxyethylene hydroxymethylphosphonate (manufactured by CBW, trade name: Wofaplexx33, m + n = 5, Mw: 332) was added to a polyester composition. 0.038 mol was added based on the weight of the product.

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 290 ° C. and a vacuum of 50 Pa. It was. The polyester composition was taken out when the target stirring power was reached. The properties of this polyester composition are shown in Table 2.
The obtained chip was dried at 160 ° C. for 2 hours, melt-extruded into a sheet at 290 ° C., and then adhered and solidified on a rotary cooling drum having a surface temperature of 30 ° C. to obtain an unstretched film. This unstretched film was stretched 3.5 times in the longitudinal direction and 3.5 times in the transverse direction at 120 ° C. and heat-set at 180 ° C. to obtain a biaxially stretched film. The properties of the obtained film are shown in Table 2.

[Examples 2-6, Comparative Examples 1-3]
The same operation as in Example 1 was repeated except that the type and amount of the phosphorus compound (phosphonate compound) were changed as shown in Table 2. In Example 3, the same operation was repeated except that the amount of diantimony trioxide added was changed to 0.015 mol, and in Example 4, the amount of diantimony trioxide added was changed to 0.02 mol. The properties of the obtained polyester composition and film are shown in Table 2.

[Examples 7 to 8]
Instead of dimethyl terephthalate (DMT), 100 mol of terephthalic acid (TA) and 200 mol of ethylene glycol (EG) were charged into a transesterification reactor, and the temperature was raised to 190 ° C. Thereafter, water was removed while raising the temperature to 240 ° C. to complete the esterification reaction. After the esterification reaction, the same operation as in Example 1 was repeated except that the type and amount of the phosphorus compound (phosphonate compound) were changed as shown in Table 2. The properties of the obtained polyester composition and film are shown in Table 2.

[Example 9, Comparative Example 4]
100 mol of dimethyl terephthalate (DMT), 200 mol of ethylene glycol (EG) and 0.03 mol of manganese acetate tetrahydrate were charged into a transesterification reactor, and the temperature was raised to 190 ° C. Subsequently, it added so that it might become 0.01 weight% on the basis of the weight of the polyester from which the average particle diameter obtained by the alkoxide method as a 10 weight% ethylene glycol slurry can obtain the spherical silica particle of 0.1 micrometer. Thereafter, methanol was removed while raising the temperature to 240 ° C. to complete the transesterification reaction.
After the transesterification reaction, the same operation as in Example 1 was repeated except that the type and amount of the phosphorus compound (phosphonate compound) were changed as shown in Table 2. The properties of the obtained polyester composition and film are shown in Table 2.

[Comparative Example 5]
The same operation as in Example 6 was repeated except that 0.08% by weight was added based on the weight of the polyester from which the true spherical silica particles used in Example 9 were obtained. The properties of the obtained polyester composition and film are shown in Table 2.

  In the types of phosphonate compounds in Table 2, A represents dioxyethylene trioxyethylene hydroxymethyl phosphonate, B represents monooxyethylene dioxyethylene hydroxymethyl phosphonate (the following formula (II)), and C represents triethyl phosphonoacetate. To do.

  According to the present invention, a polyester composition having very little internal haze can be produced, and when it is used for a film, it can be made a film having extremely excellent transparency. Therefore, it can be suitably used for, for example, a base film for optical use where high transparency is required.

Claims (6)

A polyester composition in which a phosphonate compound represented by the following structural formula (I) is used as a deactivator for a polymerization reaction in a range of 15 to 120 mmol% in terms of phosphorus element, based on the number of moles of all acid components of the polyester. A polyester composition characterized in that the content of externally added particles having an average particle diameter of 0.05 μm or more is less than 0.1% by weight.

(In the formula, ^{R 1} and ^{R 2} are each an alkylene group having 2 or more carbon atoms, m and n are positive integers, m + n is in the range of 3-10.)   The polyester composition according to claim 1, wherein no externally added particles are added.   The polyester composition according to claim 1, comprising an Sb compound in the range of 80 to 200 ppm in terms of the amount of Sb element, based on the weight of the obtained polyester composition.   The polyester composition according to claim 1, wherein the polyester is polyethylene terephthalate or polyethylene-2,6-naphthalenedicarboxylate.   The polyester film which consists of a polyester composition in any one of Claims 1-4.   In the polyester polymerization step, the catalyst deactivator is obtained without adding externally added particles having an average particle size of 0.05 μm or more in a proportion of 0.1% by weight or more based on the weight of the obtained polyester composition. A polyester composition characterized in that the phosphonate compound represented by the structural formula (I) is added so that the amount of phosphorus element is in the range of 15 to 120 mmol% with respect to the total acid component of the obtained polyester. Production method.