JP5018268B2 - Polyester manufacturing method - Google Patents

Description

  The present invention is a method for producing an alicyclic component-containing polyester in which the generation of gelled products during continuous production is suppressed. More specifically, the present invention relates to a method for producing a polyester that suppresses the generation of a gelled product during continuous production by slurrying an alicyclic diol and adding it to a reaction vessel at a specific temperature, followed by esterification or transesterification.

  Polyester containing an alicyclic component has optical properties, crystallization properties, and mechanical properties different from those of aromatic polyesters such as polyethylene terephthalate (hereinafter referred to as PET). Used in combination. However, the alicyclic diol, which is one of the alicyclic components, has a problem that the ring-opening occurs when exposed to high temperature, moisture or acid, and a gelled product is formed in the resulting polyester.

  As a method for suppressing the generation of gelled product, for example, in Patent Document 1, a polyester in which a phosphorus-based antioxidant or the like is blended is used, and in Patent Document 2, a method of controlling the carboxyl group concentration and water content during the transesterification reaction. Has been proposed.

However, in the above-described method, the alicyclic diol cannot be prevented from opening due to exposure of the alicyclic diol to high temperature, moisture and acid at the time of charging to the reaction can, and the effect of suppressing gelation is not sufficient. . In addition, when alicyclic diol scatters during charging into the reaction can and adheres to the can wall and the stirring shaft of the reaction can, it adheres when produced continuously in a batch production system. The resulting alicyclic diol is exposed to a high temperature, causing gelation.
JP 2004-67830 A JP-A-2005-314643

  The object of the present invention is to solve the above-mentioned conventional problems and to provide a method for producing a gelled product of an alicyclic diol, particularly a polyester that suppresses the generation of a gelled product during continuous production in a batch production system. is there.

An object of the present invention is to produce an alicyclic diol component as an alkali compound when producing a polyester satisfying the following formulas (1) and (2) containing at least an alicyclic dicarboxylic acid component and an alicyclic diol component . This is achieved by a method for producing a polyester, characterized in that the slurry is supplied to a reaction vessel having a can internal temperature of 100 ° C. or less, followed by esterification or transesterification, followed by polycondensation. .

65 ° C. ≦ Glass transition temperature by differential scanning calorimetry ≦ 90 ° C. (1)
1.500 ≦ refractive index at sodium D line ≦ 1.570 (2)

  According to the present invention, it is possible to produce a polyester in which scattering during addition of an alicyclic diol and generation of a gelled product due to high temperature, moisture and acid are suppressed.

  The polyester production method according to the present invention can obtain a polyester film having a low photoelastic coefficient suitable for a liquid crystal display, and can obtain a laminated polyester film excellent in light reflectivity.

In the production method of the polyester of the present invention, when producing a polyester satisfying the following formulas (1) and (2) containing at least an alicyclic dicarboxylic acid component and an alicyclic diol component, the alicyclic diol component is converted into an alkaline compound. In a method for producing a polyester, the slurry is supplied to a reaction can having a can internal temperature of 100 ° C. or less as a slurry containing , followed by an esterification reaction or a transesterification reaction, followed by a polycondensation reaction.

65 ° C. ≦ Glass transition temperature by differential scanning calorimetry ≦ 90 ° C. (1)
1.500 ≦ refractive index at sodium D line ≦ 1.570 (2)
The polyester produced by the production method of the present invention must have a glass transition temperature (hereinafter referred to as Tg) in the range of 65 ° C to 90 ° C.

  When Tg is less than 65 ° C., the heat resistance is insufficient, so that the optical properties of the resulting polyester or its molded product are likely to change with time, and when used for the purpose of forming a laminated film with PET or the like, Since the Tg difference is increased, uneven lamination or the like occurs and film formation stability is impaired. When a laminated film is used, it is preferable to match the Tg of the polyester obtained by the production method of the present invention with the Tg of the laminated polymer, and the difference between the Tg (Tg1) of the laminated polymer and the Tg (Tg2) of the polyester in the present invention (| Tg1−Tg2 |) is preferably within 10 ° C., more preferably within 5 ° C.

  When the Tg exceeds 90 ° C., the Tg difference becomes too large when laminating PET, etc., and as described above, laminating unevenness and the like occur, film formation stability is impaired, and the refractive index of the polyester is lowered. It becomes difficult to do. Therefore, the Tg of the polyester in the present invention is preferably in the range of 70 to 87 ° C, more preferably in the range of 75 to 85 ° C.

  About the refractive index of polyester obtained by the manufacturing method of this invention, it is necessary to exist in the range of 1.500-1.570. It is difficult for polyester to make the refractive index less than 1.500, and when it exceeds 1.570, the difference in refractive index from the laminated polymer becomes small, so the light reflectivity of the obtained laminated film becomes small. . Furthermore, the refractive index of the polyester obtained by the production method of the present invention is preferably in the range of 1.510 to 1.560. In addition, the refractive index in this invention points out the refractive index measured using the sodium D line | wire on 23 degreeC conditions.

In the production method of the present invention, the polyester needs to contain at least an alicyclic dicarboxylic acid component and an alicyclic diol component in order to give the above-described properties. The aromatic ring contained in the polyester has the effect of increasing Tg, but at the same time has the effect of increasing the refractive index and increasing the photoelastic coefficient.
When the photoelastic coefficient is large, the phase difference changes greatly when a stress is applied to the film, so that it is not suitable for a film for use in a liquid crystal display.

  Therefore, in the present invention, the refractive index and the photoelastic coefficient are reduced by substituting this aromatic ring component with an alicyclic dicarboxylic acid component or an alicyclic diol. Examples of the alicyclic dicarboxylic acid component in the present invention include a cyclohexane dicarboxylic acid component and a decalin dicarboxylic acid component. In particular, a cyclohexanedicarboxylic acid component is preferable from the viewpoint of availability and polycondensation reactivity. As the cyclohexanedicarboxylic acid component, cyclohexanedicarboxylic acid or an ester thereof can be used as a raw material.

  The alicyclic component such as the cyclohexanedicarboxylic acid component includes a cis isomer and a trans isomer as stereoisomers. In the present invention, the trans isomer ratio is preferably 40% or less. If the ratio of the transformer body is high, the photoelastic coefficient tends to increase, so that it tends to be poor. In addition, since the trans isomer has a higher melting point than the cis isomer, if the trans isomer ratio is high, it easily coagulates and settles during storage at room temperature or during transportation, resulting in heterogeneity and reactivity. Not only is it worse, but workability is also worse in handling. Therefore, the trans isomer ratio is preferably 35% or less, and more preferably 30% or less.

  As an alicyclic diol in this invention, a spiroglycol component and an isosorbide component are preferable, and a spiroglycol component is preferable from a viewpoint of the color tone of the polyester obtained especially. Here, spiroglycol refers to 3,9-bis (2-hydroxy-1,1-dimethylethyl) -2,4,8,10-tetraoxaspiro [5,5] undecane.

  In the present invention, for example, in the case of PET, Tg decreases when the terephthalic acid component (aromatic ring component) is substituted with cyclohexanedicarboxylic acid or the like. Then, Tg rises by substituting alicyclic diol components, such as a spiro glycol component and an isosorbide component, with an ethylene glycol component, and as a result, it can adjust to Tg comparable to PET laminated | stacked with the polyester of this invention. The effect of increasing Tg is significant in spiroglycol components and isosorbide components.

  In the production method of the present invention, it is necessary to carry out esterification or transesterification after supplying the alicyclic diol as a slurry to the reaction can from the viewpoint of suppressing gelation. When the alicyclic diol is charged without forming a slurry, gelation of the resulting polyester occurs due to the ring opening of the alicyclic diol due to the influence of temperature, moisture and acid, or the alicyclic diol is scattered during the charging. As a result, the alicyclic diol adheres to the can wall and the stirring shaft of the reaction can and is exposed to a high temperature, and a gelled product is generated during continuous production. The gelled product referred to here is an insoluble material when the polyester resin composition is heated in a nitrogen atmosphere under the conditions of 300 ° C. × 2.5 hr and then the polyester is dissolved in ortho-chlorophenol. . In the case of polyester with a large amount of gelled product, for example, when it is discharged into a strand after polycondensation, the shape becomes fussy and cannot be cut with a cutter, or a large amount of gelled product in the filter filtration process when forming a film As a result, the filtration pressure may rise abnormally, the surface defects of the laminated film may increase, and the laminated thickness of the multilayer laminated film may vary. In the present invention, by supplying the alicyclic diol as a slurry, the influence of the high temperature, moisture, and acid of the alicyclic diol is reduced, and adhesion to the reaction vessel due to the scattering of the alicyclic diol is prevented. Therefore, it is possible to suppress the generation of the gelled polyester.

  The dispersion medium for slurrying the alicyclic diol is not particularly limited, but it is preferable to use an aliphatic diol used when producing the polyester, and when the polyester is a PET system, it is ethylene glycol. Is preferred. The concentration of the alicyclic diol slurry is not particularly limited, but is preferably 50% by weight or less from the viewpoint of slurrying and handling during supply to the reaction can.

  In the production of polyester, the reaction vessel generally comprises an esterification or transesterification reaction vessel and a polycondensation reaction vessel. When continuous production is performed in such a process, the esterification or transesterification reaction is caused by the residual heat of the previous batch. Since the can is at a high temperature and the alicyclic diol supplied is ring-opened by the influence of heat, a gelled product is generated, so the inside of the can when the alicyclic diol slurry is supplied to the reaction can The temperature needs to be 100 ° C. or lower. Preferably it is 90 degrees C or less, More preferably, it is 80 degrees C or less. The inside temperature of the can here refers to the temperature of the can wall and the contents in the reaction can. When the temperature in the can exceeds 100 ° C., ring opening of the alicyclic diol due to heat occurs, and a gelled product is generated in the resulting polyester.

The alicyclic diol slurry in the present invention needs to contain an alkali compound from the viewpoint of suppressing gelation. Although it does not specifically limit as content of an alkali compound, It is preferable that it is 5-50 ppm with respect to an alicyclic diol slurry from the point of the effect on suppression of a gelled material, and the influence on the physical property of polyester. By containing an alkali compound, the effects of acids such as dicarboxylic acid components such as terephthalic acid and transesterification catalysts such as manganese acetate on alicyclic diols are alleviated and the generation of gelled products is suppressed. Can do. Examples of the alkali compound to be used include sodium hydroxide, potassium hydroxide and lithium hydroxide, but are not particularly limited.

  The alicyclic diol slurry in the present invention preferably has a moisture content of 1000 ppm or less, more preferably 500 ppm or less, and even more preferably 200 ppm or less in order to suppress the influence of moisture on the alicyclic diol. When the water content of the slurry exceeds 1000 ppm, the alicyclic diol may be ring-opened due to the influence of water in the slurry and a gelled product may be generated.

  In the polyester of the present invention, it is preferable to use at least one selected from an antimony compound, a titanium compound, and a germanium compound as a polycondensation catalyst, and it is particularly preferable to use a titanium compound from the viewpoint of suppressing gelation.

  In the method for producing the polyester of the present invention, when a titanium compound is used as the polycondensation catalyst, the titanium compound is a titanium compound whose substituent is at least one of an alkoxy group, a phenoxy group, an acylate group, an amino group, and a hydroxyl group. Preferably used.

  Specific alkoxy groups include tetraethoxide, tetrapropoxide, tetraisopropoxide, tetrabutoxide, titanium tetraalkoxide such as tetra-2-ethylhexoxide, β-diketone functional groups such as acetylacetone, lactic acid, Examples include hydroxy polyvalent carboxylic acid functional groups such as malic acid, tartaric acid, salicylic acid, citric acid, and ketoester functional groups such as methyl acetoacetate and ethyl acetoacetate, with aliphatic alkoxy groups being particularly preferred. Examples of the phenoxy group include phenoxy and cresylate. The acylate groups include tetraacylate groups such as lactate and stearate, phthalic acid, trimellitic acid, trimesic acid, hemimellitic acid, pyromellitic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid , Functional groups of polycarboxylic acids such as sebacic acid, maleic acid, fumaric acid, cyclohexanedicarboxylic acid or their anhydrides, ethylenediaminetetraacetic acid, nitrilotripropionic acid, carboxyiminodiacetic acid, carboxymethyliminodipropionic acid, diethylenetria Nitrogenous polyvalent carboxylic acid functional groups such as minopentaacetic acid, triethylenetetraminohexaacetic acid, iminodiacetic acid, iminodipropionic acid, hydroxyethyliminodiacetic acid, hydroxyethyliminodipropionic acid, methoxyethyliminodiacetic acid Especially aliphatic asylum Group is preferred. Examples of the amino group include aniline, phenylamine, diphenylamine and the like. Further, diisopropoxybisacetylacetone and triethanolaminate isopropoxide containing two kinds of these substituents can be mentioned.

  In the polyester of the present invention, the amount of titanium atom in the polyester is preferably 0.5 ppm or more and 100 ppm or less, more preferably 5 to 70 ppm, and still more preferably 10 to 10 ppm, on the basis of weight, from the viewpoint of gelation suppression and polymerization activity. 50 ppm. If it exceeds 100 ppm, gelation may be promoted by increasing the amount of metal contained. In addition, when it is less than 0.5 ppm, the polymerization activity is not sufficient, so that the target polymer solution viscosity (IV) is not reached, and as a result, the residence time at a high temperature is prolonged and gelation is promoted. It is not preferable because it may be.

  In the production method of the present invention, the titanium catalyst is preferably added to the reaction system before depressurization in the polymerization reactor is started. However, it is preferred that no titanium catalyst be present in the step of producing a low polymer from the dicarboxylic acid component and the diol component by transesterification or esterification reaction. When a titanium catalyst is added before or during the reaction for obtaining a low polymer, fine particles resulting from the titanium catalyst are generated, and turbidity is generated in the obtained polyester. Most preferably, the timing of addition of the titanium catalyst is selected after the transesterification reaction or esterification reaction for obtaining the low polymer is substantially completed and before the pressure in the reaction vessel is reduced.

  In the production method of the present invention, it is preferable to add a heat-resistant stabilizer containing a trivalent phosphorus element because an effect of suppressing the generation of gelled product tends to be obtained. A commercially available heat stabilizer can be applied as the heat stabilizer containing the trivalent phosphorus element, and examples of such phosphorus compounds include phosphorous esters, alkyl diarylphosphites, and diarylphosphites. Aryl, arylphosphonous acid dialkyl, and arylphosphonous acid diaryl, such as triphenyl phosphite, tris (4-monononylphenyl) phosphite, tri (monononyl / dinonyl phenyl) phosphite, Tris (2,4-di-tert-butylphenyl) phosphite, monooctyl diphenyl phosphite, monodecyl diphenyl phosphite, bis [2,4- (bis 1,1-dimethylethyl) -6-methylphenyl] ethyl Phosphite, tetrakis (2,4-di-te t-butylphenyl) 4,4′-biphenylenediphosphite, tris (2,4-di-tert-butylphenyl) phosphite, bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol -Di-phosphite, bis (2,4-di-tert-butylphenyl) pentaerythritol-di-phosphite, 3,9-bis (2,4-dicumylphenoxy) -2,4,8,10- Tetraoxa-3,9-diphosphaspiro [5.5] undecane, phenyl-neopentylene glycol-phosphite, 2,2-methylenebis (4,6-di-tert-butylphenyl) octyl phosphite, bis (2,4 -Dicumylphenyl) pentaerythritol diphosphite, tetra (C12-C15 alkyl) -4,4 ' It can be exemplified isopropylidene diphenyl diphosphite, and the like.

  In the method for producing the polyester of the present invention, a phosphorus compound other than the heat stabilizer containing the trivalent phosphorus element may be used. For example, phosphoric acid, phosphorous acid, phosphonic acid, phosphinic acid compound Among these, these ester compounds are preferably used in combination with a trivalent phosphorus compound.

  In the polyester of the present invention, the amount of phosphorus atoms in the polyester is preferably 70 ppm or more and 300 ppm or less, more preferably 90 to 270 ppm, and still more preferably 100 to 250 ppm, from the viewpoint of suppressing gelation. When the content is less than 70 ppm, the thermal stability of the polyester is insufficient, and heat-degraded foreign matter is generated during the polycondensation reaction, or a heat-degraded product is generated as a film defect during film formation over a long period of time. There is. On the other hand, when it exceeds 300 ppm, it reacts with a reaction catalyst etc., produces | generates an internal particle, and may become a fault of a film.

  In the present invention, the polycondensation temperature is preferably as low as possible from 260 to 290 ° C. from the viewpoint of thermal deterioration of the polyester during the polycondensation reaction and suppression of coloring. The polycondensation temperature is usually the final constant temperature because the temperature is gradually raised from 230 to 240 ° C., and after reaching a certain target temperature, polycondensation is performed at a constant temperature. When the temperature is higher than 290 ° C, the polycondensation reaction is promoted, but a heat-degraded product is likely to be generated. When the temperature is lower than 260 ° C, the polymerization activity is reduced, and the polymerization time is delayed to generate a heat-degraded product. It is not preferable because it is easy to do.

  In the present invention, the polyester preferably has a molar number of aromatic rings contained in 1 kg of polyester of 4.8 mol or less, more preferably 4.0 mol or less, in order to reduce the refractive index and photoelastic coefficient. More preferably, it is 2.0 mol or less. When it exceeds 4.8 mol, the refractive index and the photoelastic coefficient tend to increase, which is not preferable. The number of moles of aromatic rings in the present invention is based on the number of moles of benzene rings. The definition in the present invention will be described using PET and polyethylene naphthalate (hereinafter PEN) as examples.

  In the case of PET, since the molecular weight of the basic repeating unit is 192, the number of basic repeating units per kg of the polymer is 5.2. Since 1 mol of the terephthalic acid component (corresponding to one benzene ring) is contained in the basic repeating unit, the number of moles of aromatic ring of PET is calculated to be 5.2. On the other hand, in the case of PEN, the molecular weight of the basic repeating unit is 242 and the number of basic repeating units per kg of the polymer is 4.1. Although 1 mole of naphthalene dicarboxylic acid component is contained in the basic repeating unit, since the naphthalene ring corresponds to 2 benzene rings, the number of moles of aromatic ring of PEN is calculated as 8.2 moles.

  In the present invention, the polyester contains at least an alicyclic dicarboxylic acid component and an alicyclic diol component, and the other dicarboxylic acid component is selected from 2,6-naphthalenedicarboxylic acid component, terephthalic acid component, and isophthalic acid component. It is preferable to contain 20 to 95 mol% of at least one dicarboxylic acid component based on the total dicarboxylic acid component. Moreover, about a glycol component, it is preferable to contain 20-95 mol% of ethylene glycol components as a diol component. When the above-mentioned aromatic dicarboxylic acid component is less than 20 mol%, it becomes difficult to make Tg 65 ° C. or higher, for example, when laminating with PET or PEN, the interlaminar adhesion with these polyesters deteriorates. come. Similarly, when the ethylene glycol component is less than 20 mol%, interlayer adhesion with these polyesters deteriorates when laminated with PET or PEN. On the other hand, when the aromatic dicarboxylic acid component exceeds 95 mol%, it is difficult to reduce the refractive index and the photoelastic coefficient. When the ethylene glycol component exceeds 95 mol%, the Tg may be 65 ° C. or higher. It becomes difficult.

  In the polyester of the present invention, the content of the alicyclic dicarboxylic acid component and the alicyclic diol is preferably in the range of 5 to 80 mol%, more preferably 8 to 50 mol% from the above description.

  In the present invention, the polyester is preferably amorphous, and is substantially amorphous within the above-mentioned copolymerization range. The term “amorphous” in the present invention means that the heat of fusion is 4 J / g or less in DSC measurement. Such an amorphous polyester is preferable because its optical properties are not easily changed in film production.

  On the other hand, such an amorphous polyester tends to be heat-sealed by drying and easily form a lump. Therefore, by including 5 to 50% by weight of crystalline polyester, lump formation due to drying can be suppressed. As such a crystalline polyester, it is preferable that the heat of crystal fusion in differential scanning calorimetry is 4 J / g or more.

  As a method of including the crystalline polyester, melt kneading by a vent type extruder is preferable. That is, it is a method of obtaining pellets by melting and kneading the crystalline polyester and the polyester of the present invention with a vent type extruder. Examples of the crystalline polyester include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, and copolymers thereof, and polyethylene terephthalate is most preferable.

  The aromatic dicarboxylic acid component contained in the polyester in the present invention is at least selected from the types described above, but from the viewpoint of refractive index and photoelastic coefficient, a terephthalic acid component and an isophthalic acid component are preferable, and these are used simultaneously. It doesn't matter. In particular, the terephthalic acid component is preferably used mainly from the viewpoint of adhesion to other polyesters. As other dicarboxylic acid components, conventionally known ones may be copolymerized as long as the characteristics allow, and the same applies to glycol components. Examples of such components include aliphatic dicarboxylic acids such as adipic acid and sebacic acid and esters thereof, aromatic dicarboxylic acids such as 4,4′-bisphenylenedicarboxylic acid, 5-sodiumsulfoisophthalic acid, diphenic acid, and the like. Examples thereof include glycol components such as esters, diethylene glycol, butanediol, propanediol, polyethylene glycol, and polytetramethylene glycol. Further, inorganic particles, organic particles, dyes, pigments, antistatic agents, antioxidants, waxes and the like may be contained.

  In the present invention, the polyester preferably contains an element selected from an alkali metal, an alkaline earth metal, Zn, Co, and Mn as a metal component. By containing these metal elements, electrostatic applicability at the time of forming a polyester film is improved. In the case of an alkali metal, K is more preferable because Na easily colors the polyester yellow. In the alkaline earth metal, Mg is more preferable because Ca easily forms foreign matters. Of Zn, Co, and Mn, Mn is preferable from the viewpoint of foreign matter and color tone. Among these, Mg and Mn are preferable from the viewpoint of the transparency of the resin, and Mn is particularly preferable.

  The aforementioned metal compound may also serve as a transesterification catalyst. In particular, a manganese compound is preferable because of its strong activity in transesterification. The metal compound is preferably soluble in polyester, and is preferably a hydroxide, chloride or acetate, and particularly preferably acetate.

  Next, each method for producing the polyester and film of the present invention will be described in detail.

  In the polyester production method of the present invention, a low polymer is synthesized by esterifying a dicarboxylic acid and a diol, and then polycondensed with the dicarboxylic acid and a diol to transesterify the low polymer. A method of synthesizing and then polycondensing this can be employed. Since spiroglycol is easily decomposed by an acid component, it is preferably polymerized by transesterification to avoid decomposition.

  In the case of the transesterification method, the temperature in the can is adjusted so that a slurry of spiroglycol containing an alkali compound using dimethyl terephthalate, dimethylcyclohexanedicarboxylate, ethylene glycol, ethylene glycol as a dispersion medium as a raw material has a predetermined polymer composition. Charge to a reaction can below 100 ° C. In this case, if ethylene glycol is added by 1.7 to 2.3 mole times the total dicarboxylic acid component, the reactivity is improved. After melting these at about 150 ° C., manganese acetate or the like is added as a transesterification catalyst. At 150 ° C., these monomer components become a homogeneous molten liquid. Next, methanol is distilled while raising the temperature in the reaction vessel to 235 ° C., and the ester exchange reaction is carried out. After the transesterification is thus completed, a transesterification catalyst deactivator such as trimethyl phosphoric acid is added.

  Next, a polycondensation catalyst such as titanium citrate chelate or antimony trioxide is added. When the addition of the polycondensation catalyst is completed, the reaction product is charged into the polymerization apparatus, and the internal pressure of the apparatus is reduced from normal pressure to 133 Pa or lower while the internal temperature is slowly raised to 285 ° C. As the polycondensation reaction proceeds, the viscosity of the reaction product increases. When the predetermined stirring torque is reached, the reaction is terminated, and the polyester is discharged from the polymerization apparatus into a water tank. The discharged polyester is quenched in a water tank and made into chips with a cutter.

  Polyester can be obtained in this way, but the above is an example, and the monomer, catalyst, and polymerization conditions are not limited thereto.

  The polyester thus obtained has a low photoelastic coefficient and is suitable as a liquid crystal display film. Moreover, the film which laminated | stacked polyester of this invention, PET, etc. alternately is excellent in light reflectivity, and is suitable for a reflector use.

  The present invention will be described more specifically with reference to the following examples.

In addition, the measuring method of a physical property and the evaluation method of an effect were performed in accordance with the following method.
(1) Thermal properties of polyester (glass transition point, heat of crystal melting)
About 10 mg of the sample to be measured was weighed, sealed with an aluminum pan and pan cover, and measured with a differential scanning calorimeter (DSC7 model, manufactured by Perkin Elmer). In the measurement, the temperature was raised from 20 ° C. to 285 ° C. at a rate of 16 ° C./min in a nitrogen atmosphere, then rapidly cooled with liquid nitrogen, and again from 20 ° C. to 285 ° C. at a rate of 16 ° C./min. Raise the temperature. The glass transition point was measured in the second temperature raising process.

The amount of heat of crystal melting was calculated from the area of the crystal melting peak appearing in the second temperature raising process.
(2) Refractive index of polyester A 100-micrometer-thick unstretched sheet is obtained by melt-extruding polyester. Subsequently, the refractive index was measured with an “Abbe refractometer NAR-4T” manufactured by Atago Co., Ltd. under a temperature condition of 23 ° C. using sodium D line as a light source.
(3) Intrinsic viscosity Intrinsic viscosity was measured at 25 ° C using orthochlorophenol as a solvent.
(4) Moisture content of alicyclic diol slurry The water content of 0.3 ml of the slurry was measured with a Karl Fischer type moisture measuring device (manufactured by Kyoto Electronics Co., Ltd., MKF-12).
(5) Amount of polyester gelled product 1 g of polyester is freeze-pulverized to form a powder having a diameter of 300 μm or less and vacuum-dried. This sample is heat-treated in an oven at 300 ° C. for 2.5 hours in a nitrogen atmosphere. This is dissolved in 50 ml of orthochlorophenol (OCP) at a temperature of 80-150 ° C. for 0.5 hour. Subsequently, it is filtered through a Buchner type glass filter (maximum pore size 20-30 μm), washed and vacuum dried. The weight of the OCP insoluble matter remaining on the filter is calculated from the increase in the weight of the filter before and after filtration, and the weight fraction of the OCP insoluble matter relative to the weight of the polyester resin composition (1 g) is obtained. did.

A gelled material amount of 10% by weight or less was regarded as acceptable.
(6) Cis and trans isomer ratio of cyclohexanedicarboxylic acid A sample was diluted 5 to 6 times with methanol, and 0.4 μl of the diluted solution was measured by liquid chromatography under the following conditions.
Device: Shimadzu LC-10ADvp
Column: Capillary column DB-17 manufactured by Agilent Technologies (length 30 m, inner diameter 0.32 mm, film thickness 0.25 μm)
Temperature rising conditions: initial temperature 110 ° C., initial time 25 minutes, temperature rising rate 6 ° C./min, final temperature 200 ° C.
(7) Content of Titanium Element, Phosphorus Element, Antimony Element, and Germanium Element in Polyester Using a fluorescent X-ray apparatus (model number MESA-500W) manufactured by HORIBA, Ltd., the intensity of the fluorescent X-ray of the polymer was measured. This value was converted to metal content using a calibration curve prepared in advance with a sample with known content.
(8) Photoelastic coefficient (× 10 ⁻¹² Pa ⁻¹ )
A sample having a short side of 1 cm and a long side of 7 cm was cut out. The thickness of this sample is d (μm). Using this sample, TRANSDUCER U3C1-5K manufactured by Shimadzu Corporation, the checker was placed 1 cm above and below, and a tension (F) of 1 kg / mm ² (9.81 × 10 ⁶ Pa) was applied in the long side direction. . In this state, the phase difference R (nm) was measured using a polarizing microscope 5892 manufactured by Nikon Corporation. Sodium D line (589 nm) was used as a light source. These numerical values were applied to photoelastic coefficient = R / (d × F) to calculate the photoelastic coefficient.

The case where the photoelastic coefficient was less than 100 was regarded as acceptable.
(9) Reflectance A spectrophotometer (U-3410 Spectrophotometer) manufactured by Hitachi, Ltd. was fitted with a φ60 integrating sphere 130-0632 (Hitachi Ltd.) and a 10 ° inclined spacer, and the peak value of the reflectance was measured. The band parameter was set to 2 / servo, the gain was set to 3, and the range from 187 nm to 2600 nm was set to 120 nm / min. Measured at a detection speed of In order to standardize the reflectance, an attached BaSO ₄ plate was used as a standard reflecting plate. In this evaluation method, since the relative reflectance is obtained, the reflectance may be 100% or more.
(10) Peelability The test was conducted according to JIS K5600 (2002). The film was regarded as a hard substrate, and 25 lattice patterns were cut at intervals of 2 mm. Further, a tape cut to a length of about 75 mm was adhered to the lattice portion, and the tape was peeled off at an angle close to 60 ° in a time of 0.5 to 1.0 seconds. Here, Sekisui's cello tape (registered trademark) no. 252 (width 18 mm) was used. The evaluation result was expressed by the number of lattices in which one lattice was completely separated. When the thickness of the test film was less than 100 μm, a sample in which the test film was firmly bonded to the biaxially stretched PET film (Toray “Lumirror” T60) having a thickness of 100 μm with an adhesive was used for the peel test. . At this time, a test was performed by cutting a grid in the surface of the test sample so as not to penetrate the test sample. The number of peeling was 4 or less.

  The method for synthesizing the catalyst is described below.

Reference Example 1 (Catalyst A. Method for Synthesizing Citric Acid Chelate Titanium Compound)
Citric acid monohydrate (532 g, 2.52 mol) was dissolved in warm water (371 g) in a 3 L flask equipped with a stirrer, condenser and thermometer. To this stirred solution was slowly added titanium tetraisopropoxide (288 g, 1.00 mol) from the addition funnel. The mixture was heated to reflux for 1 hour to produce a cloudy solution from which the isopropanol / water mixture was distilled under vacuum. The product was cooled to a temperature below 70 ° C., and a 32 wt / wt% aqueous solution of NaOH (380 g, 3.04 mol) was slowly added via a dropping funnel to the stirred solution. The resulting product was filtered and then mixed with ethylene glycol (504 g, 80 mol) and heated under vacuum to remove isopropanol / water and a slightly cloudy light yellow product (Ti content 3 .85% by weight).

Reference Example 2 (Catalyst B. Method for Synthesizing Lactic Acid Chelate Titanium Compound)
Ethylene glycol (218 g, 3.51 mol) was added from a dropping funnel to titanium tetraisopropoxide (285 g, 1.00 mol) stirred in a 2 L flask equipped with a stirrer, condenser and thermometer. . The rate of addition was adjusted so that the heat of reaction warmed the flask contents to about 50 ° C. The reaction mixture was stirred for 15 minutes and an 85 wt / wt% aqueous solution of ammonium lactate (252 g, 2.00 mol) was added to the reaction flask to give a clear pale yellow product (Ti content 6.54 wt. %).

Reference Example 1
(Synthesis of polyester)
57 parts by weight (20 parts by weight as a spiroglycol component) of slurry containing 100% of water containing ethyleneglycol as a dispersion medium and containing 35% by weight of spiroglycol (hereinafter referred to as SPG) And then charged with 67.6 parts by weight of dimethyl terephthalate, 17.4 parts by weight of dimethyl 1,4-cyclohexanedicarboxylate (hereinafter CHDA) having a cis / trans ratio of 75/25, ethylene glycol 17 parts by weight and 0.04 part by weight of manganese acetate tetrahydrate were weighed and charged into a transesterification reactor. The contents were dissolved at 150 ° C. and stirred.

  While stirring, methanol was distilled while slowly raising the temperature of the reaction contents to 235 ° C. After distilling a predetermined amount of methanol, an ethylene glycol solution containing 0.02 part by weight of triethylphosphonoacetate (hereinafter TEPA) (28 ppm as P element) was added to complete the transesterification reaction. After adding triethylphosphonoacetate, the mixture was stirred for 10 minutes, and titanium catalyst A was added to 5 ppm as titanium atoms. Thereafter, the transesterification reaction product was transferred to a polymerization apparatus.

  Next, the content of the polymerization apparatus was stirred and the pressure was reduced and the temperature was raised, and a polycondensation reaction was performed while distilling ethylene glycol. The reduced pressure was reduced from normal pressure to 133 Pa or less over 90 minutes, and the temperature was raised from 235 ° C. to 285 ° C. over 90 minutes.

  When the stirring torque of the polymerization apparatus reached a predetermined value, the inside of the polymerization apparatus was returned to normal pressure with nitrogen gas, the valve at the bottom of the polymerization apparatus was opened, and gut-shaped polyester was discharged into the water tank. The polyester gut cooled in the water tank was cut with a cutter to obtain chips.

  After the completion of the first batch of polymerization, the temperature of the polymerization apparatus was returned to the initial state, and the raw material was charged again as it was to perform the second batch of polymerization. The amount of gelled product of the obtained polyester was as good as 2.0%.

  The obtained two batches of polyester were evenly mixed to obtain polyester A.

  Similarly, a PET resin was polymerized in the same manner as described above except that 100 parts by weight of dimethyl terephthalate and 64 parts by weight of ethylene glycol were used. The obtained PET resin had an intrinsic viscosity of 0.65 and a Tg of 80 ° C.

(Formation of single-layer biaxially stretched film)
The polyester chip was supplied to the vent type twin screw extruder, melted, filtered through a metal nonwoven fabric filter, and then extruded from a T die as a molten sheet. The molten sheet was cooled and solidified on a specular drum whose surface temperature was controlled at 25 ° C. by an electrostatic application method (electrodes used a tungsten wire having a diameter of 0.15 mm) to form an unstretched sheet. The photoelastic coefficient was measured using the unstretched sheet. The photoelastic coefficient was 85 × 10 ⁻¹² Pa ⁻¹ .

(Formation of laminated polyester film)
Each of the polyester A and the PET resin was supplied to two vented twin screw extruders.

  Polyester A and PET resin were each melted by an extruder, passed through a gear pump and a filter, and then joined by a 101-layer feed block. At this time, both surface layers of the laminated film were made to be PET resin layers, and the laminated thickness was alternately laminated so that the polyester A layer / PET resin layer was ½. That is, the polyester A layer was laminated alternately so that 50 layers and the PET layer were 51 layers.

  The 101-layer laminate thus obtained was supplied to a die, extruded into a sheet, and rapidly cooled and solidified on a casting drum maintained at a surface temperature of 25 ° C. by electrostatic application (DC voltage 8 kV). .

  The obtained cast film was led to a roll type longitudinal stretching machine, heated by a group of rolls heated to 90 ° C., and stretched 3 times in the longitudinal direction between rolls having different peripheral speeds. The film that had been stretched in the machine direction was then led to a tenter-type transverse stretcher. The film was preheated with hot air at 100 ° C. in a tenter and stretched 3.3 times in the transverse direction. The stretched film was directly heat treated with hot air at 200 ° C. in a tenter. In this way, a film having a thickness of 50 μm could be obtained. The reflectance was measured using the obtained film. The reflectance was 98%.

The characteristics of the obtained polyester and film are shown in Tables 1 and 2. Since the polyester film of the present invention has a photoelastic coefficient of 85 × 10 ⁻¹² Pa ⁻¹ and a refractive index as low as 1.550, it has excellent light reflectivity when used as a laminated film.

Example 2
A slurry containing 20 ppm of potassium hydroxide was used, titanium catalyst A was added to 20 ppm as titanium atoms, and bis (2,6-di-tert-butyl-4-) produced by Asahi Denka Kogyo Co., Ltd. together with TEPA. Polyester was polymerized in the same manner as in Reference Example 1 except that 0.15 part by weight of methylphenyl) pentaerythritol-di-phosphite) (147 ppm as P element, hereinafter referred to as PEP36) was added. Furthermore, using the PET resin polymerized in Reference Example 1, a laminated film was obtained under the same conditions. The results are shown in Tables 1 and 2. Addition of potassium hydroxide and PEP36 further reduced the amount of gelled product.

Example 3
A polyester containing 20 ppm of lithium hydroxide was used, titanium catalyst B was added to 20 ppm as titanium atoms, and polyester was added in the same manner as in Reference Example 1 except that 0.15 parts by weight of PEP36 was added together with TEPA. Polymerized. Furthermore, using the PET resin polymerized in Reference Example 1, a laminated film was obtained under the same conditions. The results are shown in Tables 1 and 2. Addition of lithium hydroxide and PEP36 further reduced the amount of gelled product.

Reference Example 4
Reference Example 1 except that the amount ratio of CHDA and SPG was changed and a slurry with a water content of 300 ppm was used, titanium catalyst A was added to 20 ppm as titanium atoms, and 0.15 parts by weight of PEP36 was added together with TEPA. The polyester was polymerized in the same manner as described above. Furthermore, using the PET resin polymerized in Reference Example 1, a laminated film was obtained under the same conditions. The results are shown in Tables 1 and 2. Although the amount of gelled product was small and good, the photoelasticity slightly increased due to the large number of moles of aromatic rings.

Example 5
Reference was made except that the amount ratio of CHDA and SPG was changed and a slurry containing 20 ppm of potassium hydroxide was used, antimony trioxide was added to 20 ppm as antimony atoms, and 0.15 part by weight of PEP36 was added together with TEPA. The polyester was polymerized in the same manner as in Example 1. Furthermore, using the PET resin polymerized in Reference Example 1, a laminated film was obtained under the same conditions. The results are shown in Tables 1 and 2. Excellent light reflectivity due to sufficiently low refractive index, but the amount of copolymerization component increased, so the compatibility with PET decreased, delamination was weak, and the amount of SPG copolymerization was high, so the gelation rate Was slightly higher.

Example 6
Polyester was polymerized in the same manner as in Reference Example 1 except that slurry containing 20 ppm of potassium hydroxide was used, germanium dioxide was added to 20 ppm as germanium atoms, and 0.15 parts by weight of PEP36 was added together with TEPA. did. Furthermore, using the PET resin polymerized in Reference Example 1, a laminated film was obtained under the same conditions. The results are shown in Tables 1 and 2. The amount of gelled product was small and good, and there was almost no change in physical properties.

Example 7
A polyester was polymerized in the same manner as in Reference Example 1 except that a slurry containing 20 ppm of potassium hydroxide was used and the titanium catalyst A was added so as to be 20 ppm as titanium atoms. Furthermore, using the PET resin polymerized in Reference Example 1, a laminated film was obtained under the same conditions. The results are shown in Tables 1 and 2. The amount of gelled product was small and good, and there was almost no change in physical properties.

Example 8
Use a CHDA cis / trans isomer with a trans isomer ratio of 40%, use a slurry with a water content of 200 ppm containing 20 ppm potassium hydroxide, and add titanium catalyst A to 20 ppm as titanium atoms. The polyester was polymerized in the same manner as in Reference Example 1 except that 0.15 parts by weight of PEP36 was added together with TEPA. Furthermore, using the PET resin polymerized in Reference Example 1, a laminated film was obtained under the same conditions. The results are shown in Tables 1 and 2. Due to precipitation of the trans isomer during the polymerization, the charged piping and the like were slightly clogged, and the resulting film also had a slightly higher photoelastic coefficient due to the large amount of the trans isomer.

Example 9
Instead of CHDA, dimethyl decalinate was changed to 25 mol%, and a slurry with a water content of 500 ppm containing 20 ppm potassium hydroxide was charged while maintaining the temperature in the can of the transesterification reactor at 100 ° C., and the titanium catalyst A was used as a titanium atom. Polyester was polymerized in the same manner as in Reference Example 1 except that it was added to 20 ppm and 0.15 part by weight of PEP36 was added together with TEPA. Furthermore, using the PET resin polymerized in Reference Example 1, a laminated film was obtained under the same conditions. The results are shown in Tables 1 and 2. The amount of gelled product was slightly larger due to the influence of the moisture content and the temperature in the can when the slurry was charged.

Example 10
Instead of SPG, it was changed to 10 mol% isosorbide, and a slurry with a water content of 1000 ppm containing 20 ppm sodium hydroxide was charged while maintaining the temperature in the can of the transesterification reactor at 90 ° C. The polyester was polymerized in the same manner as in Reference Example 1 except that 0.15 part by weight of PEP36 was added together with TEPA. Furthermore, using the PET resin polymerized in Reference Example 1, a laminated film was obtained under the same conditions. The results are shown in Tables 1 and 2. The amount of gelled product was slightly larger due to the influence of the moisture content and the temperature in the can when the slurry was charged.

Comparative Example 1
In the polymerization of the polyester of Reference Example 1, the slurry was charged while maintaining the internal temperature of the transesterification reactor at 110 ° C., and antimony trioxide was added to 20 ppm as antimony atoms, and PEP36 was added together with TEPA to 0.15. A polyester was polymerized in the same manner as in Reference Example 1 except for adding parts by weight to obtain a laminated film. The results are shown in Tables 1 and 2. As the temperature in the can at the time of slurry supply was outside the specified range, the gelled product amount in the second batch was poor.

Comparative Example 2
In the polymerization of the polyester of Reference Example 1, SPG powder and 20 ppm of potassium hydroxide were weighed without making a slurry, then charged into a transesterification reactor, and antimony trioxide was added so as to be 20 ppm as antimony atoms. Polyester was polymerized in the same manner as in Reference Example 1 to obtain a laminated film. Although a result is shown in Table 1, 2, since SPG was supplied without making it a slurry, the gelled material amount of the 2nd batch was unsatisfactory.

Comparative Example 3
In the polymerization of polyester Reference Example 1, was weighed SPG powder without slurry was charged into an ester exchange reactor, except for adding to a 20ppm of titanium catalyst A as the titanium atom in Reference Example 1 Similarly, polyester was polymerized to obtain a laminated film. Although a result is shown in Table 1, 2, since SPG was supplied without making it a slurry, the gelled material amount of the 2nd batch was unsatisfactory.

Comparative Example 4
In the polymerization of the polyester of Reference Example 1, 15 mol% of isophthalic acid was copolymerized instead of CHDA, spiroglycol was not copolymerized, and antimony trioxide was added so as to be 20 ppm as an antimony atom. Reference Example Polyester was polymerized in the same manner as in Example 1 to obtain a laminated film. The results are shown in Tables 1 and 2, but the amount of gelled product is small, and since it contains neither an alicyclic dicarboxylic acid component nor an alicyclic diol component, the refractive index and photoelastic coefficient are large, and the reflectance of the laminated film is also It was small.

Comparative Example 5
In the polymerization of the polyester of Reference Example 1, CHDA is not copolymerized, and 30 mol% of cyclohexanedimethanol component slurried with ethylene glycol instead of SPG is copolymerized to be 20 ppm with antimony trioxide as antimony atoms. A polyester film was polymerized in the same manner as in Reference Example 1 except that it was added to a laminated film. The results are shown in Tables 1 and 2. Although the amount of gelled material was small and the refractive index was lowered, the photoelastic coefficient was slightly large and the reflectance of the laminated film was slightly inferior.

Comparative Example 6
In the polymerization of polyester of Reference Example 1, CHDA is not copolymerized, the SPG were slurried in ethylene glycol by polymerizing 45 mol% both the REFERENCE except that antimony trioxide was added to a 20ppm as antimony atom Polyester was polymerized in the same manner as in Example 1 to obtain a laminated film. The results are shown in Tables 1 and 2. The Tg and gelation rate were very high, and the peelability of the laminated film was inferior. In addition, there were many low molecular weight droplets during the polycondensation reaction, and the vacuum circuit was slightly blocked, resulting in poor vacuum.

Comparative Example 7
In the polymerization of the polyester of Reference Example 1, 25 mol% of CHDA was copolymerized, SPG was not copolymerized, and the polyester was added in the same manner as in Reference Example 1 except that antimony trioxide was added to 20 ppm as antimony atoms. Was polymerized to obtain a laminated film. The results are shown in Tables 1 and 2. The gelled amount was small and the refractive index was within the target range, but the Tg was lowered, the peelability of the laminated film was poor, and the reflectance was small.

Claims (12)

In producing a polyester satisfying the following formulas (1) and (2) including at least an alicyclic dicarboxylic acid component and an alicyclic diol component, the alicyclic diol component is used as a slurry containing an alkali compound, and the temperature inside the can Is supplied to a reaction vessel having a temperature of 100 ° C. or lower, followed by esterification or transesterification, followed by polycondensation.
65 ° C. ≦ Glass transition temperature by differential scanning calorimetry ≦ 90 ° C. (1)
1.500 ≦ refractive index at sodium D line ≦ 1.570 (2) 2. The method for producing a polyester according to claim 1, wherein the alicyclic diol slurry has a water content of 1000 ppm or less. The method for producing a polyester according to claim 1 or 2 , wherein the alicyclic diol component is a spiroglycol component and is contained in an amount of 5 to 80 mol% in all diol components. The method for producing a polyester according to any one of claims 1 to 3 , wherein at least one selected from an antimony compound, a titanium compound, and a germanium compound is used as the polycondensation catalyst. As a polycondensation catalyst, an alkoxy group, a phenoxy group, acylate groups, as claimed in claim 1-4, which comprises using a titanium compound having at least one substituent selected from the group consisting of amino group and a hydroxyl group The manufacturing method of polyester of any one. Alkoxy group β- diketone functional group of the titanium compound, any of claims 1-5, characterized in that at least one functional group selected from the group consisting of hydroxy carboxylic acid functional groups and keto ester based functional group A process for producing the polyester according to item 1. The method for producing a polyester according to any one of claims 1 to 6 , wherein the titanium atomic weight in the polyester is 0.5 ppm or more and 100 ppm or less. A method for producing a polyester according to any one of claims 1 to 7, wherein a trivalent phosphorus heat-resistant stabilizer is added. The method for producing a polyester according to any one of claims 1 to 8 , wherein a phosphorus atom weight in the polyester is 70 ppm or more and 300 ppm or less. The method for producing a polyester according to any one of claims 1 to 9 , wherein the alicyclic dicarboxylic acid component is a cyclohexane dicarboxylic acid component and is contained in an amount of 5 to 80 mol% in all dicarboxylic acid components. The method for producing a polyester according to any one of claims 1 to 10 , wherein a cis- and trans-isomer of a cubic isomer is contained as the cyclohexanedicarboxylic acid component, and the content of the trans-isomer is 40% or less. . The method for producing a polyester according to any one of claims 1 to 11 , wherein the number of aromatic moles contained in the repeating unit of the polyester is 4.8 moles or less in terms of 1 kg of the polyester.