JP4929616B2 - Polyester composition and polyester molded body comprising the same - Google Patents

Description

  The present invention is a polyester composition suitably used as a raw material for a molded body such as a hollow molded body, a sheet-like product, and a stretched film including a beverage bottle, particularly acetaldehyde generation during molding is suppressed, and a crystallization rate In addition, the present invention relates to a polyester composition which gives a molded article having no problem in terms of fluctuation in crystallization speed, excellent in transparency and having little fluctuation in transparency, and a polyester molded article having excellent heat resistance. In addition, the present invention relates to a polyester composition that has good releasability from a heat treatment mold when molding a hollow molded body and is excellent in long-term continuous moldability.

Polyesters such as polyethylene terephthalate (hereinafter sometimes abbreviated as “PET”) are excellent in both mechanical properties and chemical properties, and thus have high industrial value, such as fibers, films, sheets, and bottles. Widely used as such.
As a material for containers such as seasonings, oils, beverages, cosmetics, and detergents, various resins are employed depending on the type of filling contents and the purpose of use.

  Of these, polyester is excellent in mechanical strength, heat resistance, transparency and gas barrier properties, and is particularly suitable as a material for molded articles such as beverage filling containers such as juices, soft drinks and carbonated drinks. is there.

  For example, such polyester is supplied to a molding machine such as an injection molding machine to form a preform for a hollow molded body, and the preform is inserted into a mold having a predetermined shape and stretched blow molded to cool it. It is made into a hollow molded container for beverages, or it is molded into a heat-resistant or pressure-resistant hollow molded container by heat-treating the preform plug part (crystallization of the plug part) and then stretching blow molding and heat-treating the body part (heat set). It is common. However, when the crystallization of the plug portion is insufficient or the variation in crystallinity is large, the sealing performance with the cap is deteriorated, and the contents may leak.

  In order to solve such problems, in the case of beverages that require hot filling, such as fruit juice beverages, oolong tea, and mineral water, the mouth portion of the preform or molded bottle is heat-treated and crystallized. A method (for example, see Patent Document 1) is common. Such a method, that is, a method of improving the heat resistance by heat-treating the plug portion and the shoulder portion, the time and temperature for the crystallization treatment greatly affect the productivity, and can be processed at a low temperature in a short time. It is preferable that the conversion rate is PET. On the other hand, the body portion is required to be transparent even if heat treatment is performed at the time of molding so as not to deteriorate the color tone of the contents of the bottle, and the mouthpiece portion and the body portion must have contradictory characteristics.

  Moreover, in order to improve the heat resistance of a bottle trunk | drum, the method of heat-processing by making the temperature of an extending | stretching blow metal mold high is taken, for example (for example, refer patent document 2). However, if a large number of bottles are continuously formed using the same mold by such a method, the bottle obtained with a long time operation is whitened, the transparency is lowered, and only a bottle having no commercial value can be obtained. . It has been found that this is due to adhesion of PET due to the PET surface on the mold surface, resulting in mold contamination, which is transferred to the bottle surface. In particular, in recent years, the molding speed has been increased along with the downsizing of the bottle. From the viewpoint of productivity, the melting time at the time of injection molding is shortened, the heating time for crystallization of the plug portion is shortened, or the mold. Contamination has become a greater problem and is not satisfactory with conventional PET, and a solution is desired.

  Various proposals have been made to solve the problem of improvement and stabilization of the crystallization rate. For example, there are a method of adding an inorganic nucleating agent such as kaolin and talc to polyethylene terephthalate (for example, see Patent Document 3) and a method of adding an organic nucleating agent such as montanic acid wax salt (for example, see Patent Document 4). These methods are accompanied by the generation of foreign matter and cloudiness and have problems in practical use. In addition, there is a method of adding a treated polyester obtained by pulverizing a polyester molded body obtained by melt molding from the polyester to the raw material polyester (see, for example, Patent Document 5), but this method has an extra step of melt molding and pulverization. In addition, there is a risk that impurities other than polyester are mixed in such a post-process, and this is not a preferable method in terms of economy and quality. In addition, a method for producing a container using a composition comprising two kinds of polyesters having a specific range of temperature-rise crystallization temperature and a temperature-fall crystallization temperature and having different ranges of intrinsic viscosities (see, for example, Patent Document 6) However, it is difficult to produce bottles with excellent transparency and heat resistance by high-speed molding, and there is a problem in recyclability, such as adversely affecting transparency when re-molding used containers.

Also, a PET modification method by bringing a PET chip into contact with a polyethylene member under flow conditions (see, for example, Patent Document 7), or contact with a member made of polypropylene resin or polyamide resin under similar conditions A method for modifying PET by PET (for example, see Patent Document 8), a polyester resin composition in which 0.1 to 45 ppb of polyethylene is blended with a polyester resin (for example, see Patent Document 9), and the like have been proposed. Even with a simple method and polyester resin composition, it has an appropriate and stable crystallization speed, has no defects such as whitened flow patterns and bubbles, has excellent transparency, and has excellent heat-resistant dimensional stability. It turned out that it was very difficult to obtain a molded body.
Further, PET contains acetaldehyde (hereinafter sometimes abbreviated as AA) as a by-product during melt polycondensation. In addition, PET produced acetaldehyde by thermal decomposition when thermoforming a molded body such as a hollow molded body, and the acetaldehyde content in the material of the obtained molded body was increased, and the hollow molded body was filled. Affects the flavor and odor of beverages.

  In recent years, polyester containers such as polyethylene terephthalate have come to be used as containers for low flavor beverages such as mineral water and oolong tea. In the case of such beverages, these beverages are generally heat-filled or sterilized by heating after filling, but the reduction of the acetaldehyde content in the beverage container is becoming increasingly important. In addition, for beverage metal cans, for the purposes of process simplification, hygiene, pollution prevention, etc., cans are made using a metal plate whose inner surface is coated with a polyester film whose main repeating unit is ethylene terephthalate. The method to do has come to be adopted. In this case as well, it is sterilized by heating at a high temperature after filling the contents. At this time, it is found that the use of a film having a sufficiently low acetaldehyde content is an essential requirement for improving the flavor and odor of the contents. I came.

  For these reasons, various measures have been taken to reduce the acetaldehyde content in the polyester. As these measures, for example, a method of reducing the AA content by solid-phase polymerization of melt-polycondensed polyester (see, for example, Patent Document 10), AA at the time of molding using a copolyester having a lower melting point Method for reducing production (for example, see Patent Document 11), Method for reducing oligomers and aldehydes by subjecting a polyester prepolymer obtained by melt polymerization to solid phase polymerization under reduced pressure or in the flow of an inert gas (For example, refer to Patent Document 12), a method using a polyester composition in which 0.05 parts by weight or more and less than 1 part by weight of a metaxylylene group-containing polyamide resin is added to 100 parts by weight of a polyester resin (for example, refer to Patent Document 14) ) And certain polyesters with a terminal amino group concentration regulated within a certain range. A polyester container comprising an amide-containing polyester composition (see, for example, Patent Document 15), a method of crystallization and solid-phase polymerization after conditioning a polyester prepolymer so that the moisture content is 2000 ppm or more (for example, , Patent Document 16), a method in which polyester particles are treated with hot water at 50 to 200 ° C., and then heated under reduced pressure or in an inert gas flow (for example, see Patent Document 17), before and after solid-phase polymerization. A method of extracting and washing with water or an organic solvent (see, for example, Patent Document 18), a method of reducing the molding temperature as much as possible during thermoforming, a method of reducing the shear stress as much as possible during thermoforming, etc. Has been proposed. However, even in a molded body using polyester obtained by these methods, it cannot be said that oligomers and acetaldehyde can be reduced to a problem-free level, and the problem remains unsolved. In addition, a blend of solid-phase polymerized PET and copolymerized polyethylene terephthalate (for example, see Patent Document 19) has been proposed, and by using this, the AA content of the hollow molded body can be reduced. Since the copolymer component is present, there is a problem in the heat resistance and pressure resistance of the obtained molded body, which is not satisfactory and a solution is awaited.

  In recent years, thinning of bottles has been attempted, and as a result, attempts have been made to increase the molecular weight in order to increase the strength of the bottle, but by increasing the molecular weight, the melt viscosity during molding increases and the amount of acetaldehyde generated increases. There was an increasing problem.

JP 55-79237 A Japanese Examined Patent Publication No.59-6216 JP-A-56-2342 JP 57-125246 A Japanese Patent Laid-Open No. 5-105807 Japanese Patent Laid-Open No. 10-287799 JP-A-9-71639 Japanese Patent Laid-Open No. 11-209492 JP-A-9-151308 JP-A-53-73288 Japanese Patent Laid-Open No. 57-16024 JP 55-89330 A JP 55-89331 A Japanese Examined Patent Publication No. 6-6661 Japanese Examined Patent Publication No. 4-71425 JP-A-2-298512 JP-A-8-120062 Japanese Patent Laid-Open No. 55-13715 JP 58-45254 A

  The present invention solves the problems of the above conventional methods, suppresses the formation of acetaldehyde at the time of molding, has excellent transparency and little variation in transparency, and is hollow with excellent pressure resistance or heat-resistant dimensional stability. An object of the present invention is to provide a polyester composition capable of efficiently producing a polyester molded body such as a molded body, particularly a hollow molded article excellent in heat resistance by high-speed molding, and a polyester molded body comprising the same.

The inventors of the present invention have arrived at the present invention as a result of intensive studies to achieve the above object. That is, the polyester composition of the present invention is a polyester composition containing, as main components, the following polyester A and polyester B having ethylene terephthalate as the main repeating unit, and the ultimate viscosity IV _A of polyester _A and the limit of polyester B: The difference in viscosity IV _B is in the range of 0.05 to 0.30, and the difference between the crystallization temperature of Polyester A when it is raised and the crystallization temperature when Polyester B is raised is within 10 ° C., and A polyester composition characterized in that it contains 0.1 ppb to 1000 ppm of at least one resin selected from the group consisting of polyolefin resin, polyamide resin, and polyacetal resin.

Polyester A: Intrinsic viscosity IV _A is 0.60 to 0.75 deciliter / gram, acetaldehyde content is 10 ppm or less, crystallization temperature at temperature rise measured by DSC is 150 to 172 ° C., and crystallization temperature at temperature fall is Polyester that is 160-190 ° C.
Polyester B: Intrinsic viscosity IV _B is 0.73 to 0.90 deciliter / gram, acetaldehyde content is 10 ppm or less, crystallization temperature at temperature increase measured by DSC is 150 to 172 ° C., and crystallization temperature at temperature decrease is Polyester that is 160-190 ° C.

  By using the polyester composition of the present invention having the above characteristics, the flowability in the melt molding machine is improved, so that molding at a lower temperature is possible, the acetaldehyde content is lower, and the flavor retention is excellent. To obtain a hollow molded article having excellent heat resistance without generation of transparent spots (for example, a whitened flow pattern generated on the molded article or a partial whitened product or a wrinkled product). Is possible. In particular, these effects become remarkable in the case of a thick stretched molded body such as a bottle. Further, there is an advantage that the transparency and the crystallization speed are not adversely affected when a used product made of the polyester composition of the present invention is reused after being mixed with a virgin raw material by several percent.

  The polyester composition of the present invention is excellent in mechanical properties such as elastic modulus and tensile strength because the fluidity at the time of melting is improved and the orientation at the time of heating crystallization and the orientation at the time of heating stretching are also improved. A stretched molded article having excellent heat fixability can be provided, and it is usefully used as a stretched hollow container particularly excellent in heat resistance.

  In the polyester composition of the present invention, the blending ratio of the polyester A and the polyester B is 95/5 to 5/95, preferably 92/8 to 8/92, more preferably 90/10 to 10/90, in weight ratio. If it is out of this range, the object of the present invention is not achieved, which is not desirable.

  The polyester composition of the present invention is a mixture of at least two kinds of polyesters selected from the above-mentioned polyester A and polyester B, respectively, and the compositions of polyester A and polyester B are preferably substantially the same. Here, “substantially the same” means that the acid component and the glycol component in each composition are preferably 95 mol% or more, more preferably 97 mol% or more, particularly 98 mol% or more. It is preferable.

The difference between the intrinsic viscosity IV _A of polyester _A and the intrinsic viscosity IV _B of polyester B is preferably 0.06 to 0.27 deciliter / gram, more preferably 0.07 to 0.23 deciliter / gram, particularly preferably 0. 10 to 0.20 deciliters per gram. When the above-mentioned intrinsic viscosity difference is less than 0.05 deciliter / gram, the acetaldehyde content of the obtained molded product cannot be reduced, and the flavor retention cannot be improved. When the above-mentioned intrinsic viscosity difference exceeds 0.30 deciliter / gram, thickness fluctuations, whitened flow patterns, and the like occur in the obtained molded product, and the crystallization speed fluctuates greatly. Variations in size occur, resulting in capping failure and content leakage.

  Further, the difference between the crystallization temperature when the temperature of polyester A is raised and the crystallization temperature when polyester B is raised is preferably within 8 ° C, more preferably within 7 ° C, and particularly preferably within 5 ° C. When the difference of the crystallization temperature at the time of the said temperature rise exceeds 10 degreeC, the crystallization speed fluctuation | variation of the obtained molded object becomes large. As a result, for example, the variation in crystallinity of the heat-crystallized hollow molded body plug portion is large, resulting in large dimensional variation of the plug portion, resulting in poor capping properties and leakage of contents.

The intrinsic viscosity IV _A of polyester A is preferably 0.62 to 0.74 deciliter / gram, more preferably 0.65 to 0.73 deciliter / gram, and the acetaldehyde content is preferably 8 ppm or less, more preferably 5 ppm or less, The crystallization temperature at the time of temperature rise is preferably 151 to 170 ° C, more preferably 152 to 168 ° C, and the crystallization temperature at the time of temperature drop is preferably 162 to 185 ° C, more preferably 165 to 180 ° C. If the intrinsic viscosity IV _A of the polyester A is less than 0.60 dl / g is a problem deteriorates the transparency of the resulting molded product. On the other hand, if it exceeds 0.75 deciliter / gram, the effect of reducing acetaldehyde is lowered. On the other hand, when the acetaldehyde content exceeds 10 ppm, the flavor retention of the resulting molded product is deteriorated, which is problematic. On the other hand, in the economically profitable method, the limit is 1 ppm or less. Moreover, when the crystallization temperature at the time of raising the temperature of the polyester A is less than 150 ° C., the transparency of the molded article is deteriorated, and when it exceeds 172 ° C., the effect of improving the crystallization rate of the plug portion is deteriorated. When the crystallization temperature of the polyester A when the temperature is lowered is less than 160 ° C., the effect of improving the crystallization speed of the plug portion is deteriorated, and when it exceeds 190 ° C., the transparency of the molded article is deteriorated.

The intrinsic viscosity IV _B of polyester B is preferably 0.74 to 0.86 deciliter / gram, more preferably 0.75 to 0.83 deciliter / gram, and the acetaldehyde content is preferably 8 ppm or less, more preferably 5 ppm or less, The crystallization temperature at the time of temperature rise is preferably 151 to 172 ° C, more preferably 152 to 170 ° C, and the crystallization temperature at the time of temperature drop is preferably 162 to 185 ° C, more preferably 165 to 180 ° C. The intrinsic viscosity of the polyester B IV _B If there is less than 0.73 dl / g is a problem deteriorates the transparency of the resulting molded product. On the other hand, if it exceeds 0.90 deciliter / gram, heat generation during molding becomes intense and the effect of reducing acetaldehyde becomes low. On the other hand, when the acetaldehyde content exceeds 10 ppm, the flavor retention of the resulting molded product is deteriorated, which is problematic. On the other hand, in the economically profitable method, the limit is 1 ppm or less. Moreover, when the crystallization temperature at the time of raising the temperature of polyester B is less than 150 ° C., the transparency of the molded article is deteriorated, and when it exceeds 172 ° C., the effect of improving the crystallization rate of the plug is deteriorated. When the crystallization temperature of the polyester B when the temperature is lowered is less than 160 ° C., the effect of improving the crystallization rate of the plug portion is deteriorated, and when it exceeds 190 ° C., the transparency of the molded article is deteriorated.

  Further, the blending ratio of at least one resin selected from the group consisting of polyolefin resin, polyamide resin, and polyacetal resin in the polyester composition of the present invention to the polyester is preferably 0.3 ppb to 100 ppm, more preferably. Is 0.5 ppb to 10 ppm, more preferably 1.0 ppb to 1 ppm, and particularly preferably 1.0 ppb to 45 ppb. When the blending amount is less than 0.1 ppb, the crystallization speed becomes very slow and the crystallization of the plug part of the hollow molded body becomes insufficient. Therefore, if the cycle time is shortened, the shrinkage amount of the plug part is specified. Since it does not fall within the value range, capping failure occurs. If it exceeds 1000 ppm, the crystallization speed will be high, and the crystallization of the plug part of the hollow molded body will be excessive, and the shrinkage of the plug part will not fall within the specified range, resulting in capping failure. Leakage occurs, and the preform for the hollow molded body is whitened, so that normal stretching is impossible. Also, in the case of a sheet-like material, if it exceeds 1000 ppm, the transparency is very poor, the stretchability is also impaired, and normal stretching is impossible, and only a stretched film with large thickness spots and poor transparency is obtained. I can't.

  Polyester A and polyester B having different intrinsic viscosities used in the present invention were produced so that the difference in intrinsic viscosity was within the scope of the present invention in the melt polycondensation reaction step or the subsequent solid phase polymerization reaction step. Polyester or polyester obtained by subjecting these to contact treatment with water under a condition that the intrinsic viscosity does not decrease.

  As other production methods for obtaining polyesters having different intrinsic viscosities, there are a method of hydrolyzing polyester by heat treatment with water at a high temperature, a method of melt treatment with an extruder, and the like. However, since the method by hydrolysis is carried out in a solid state, it is very difficult to control the degree of IV reduction, it is difficult to obtain polyester particles having a narrow IV fluctuation range, and particles after hydrolysis treatment Is likely to generate fine powder due to impact during transportation, etc., so that there is a problem that the fluctuation of the transparency and crystallization speed of the molded body when these are used becomes very large. The fluctuation is a big problem. In addition, the method using the melt treatment has problems such as an influence on flavor retention and coloring due to an increase in aldehydes such as acetaldehyde during the treatment. Therefore, the polyester according to the present invention does not include polyester hydrolyzed by a method such as heat treatment under pressure with water or the like, or polyester melt-treated to reduce IV.

  In this case, the bulk density of the polyester A and polyester B chips is 0.80 to 0.97 grams / cubic centimeter, and the difference between the bulk density of the polyester A chips and the bulk density of the polyester B chips is 0.00. Preferably it is within 10 / cubic centimeter.

In this case, the content of the cyclic trimer is preferably 0.70% by weight or less.
In this case, it is desirable that the fine content of the polyester composition is 0.1 to 5000 ppm.

In this case, it is desirable that the fine melting point measured by DSC is 265 ° C. or less.
Here, fine means a polyester strip or fine powder that has passed through a sieve having a nominal size of 1.7 mm according to JIS-Z8801, and the content thereof is measured by the following measuring method.
In this case, it is desirable that the cyclic trimer increase amount when melted at a temperature of 290 ° C. for 60 minutes is 0.40% by weight or less.

Here, the amount of increase in cyclic trimer when melted for 60 minutes at a temperature of 290 ° C. is obtained from a 3 mm thick plate of a stepped molded plate obtained by the molding method described in the “Measurement Method” section below. This is the value obtained for the sample.
In this case, the above-mentioned polyester composition can be formed.

  In this case, the molded body may be a hollow molded body, a sheet-like material, or a stretched film obtained by stretching the sheet-like material in at least one direction.

  The polyester composition has a low acetaldehyde content, is excellent in flavor retention and transparency, has a low cyclic ester oligomer content, and is less likely to cause mold contamination during continuous molding, for example, a hollow molded product, a sheet A shape, a stretched film, etc. can be given.

The present invention provides a polyester composition that provides a molded product that has a small amount of aldehyde generated during molding due to improved flow characteristics and that has excellent mechanical properties such as pressure resistance when formed into a molded product. In addition, since the polyester composition of the present invention has improved flow characteristics, there is little distortion during molding, and a molded article having excellent heat-resistant dimensional stability, particularly a hollow molded article, can be efficiently produced by high-speed molding, and The present invention provides a polyester composition excellent in pressure resistance and heat-resistant dimensional stability, and excellent in long-time continuous moldability with less fouling of a mold and a molded body comprising the same.
The polyester composition of the present invention can meet high quality requirements in the field of containers, sheets and the like.

Hereinafter, embodiments of the polyester composition of the present invention will be specifically described.
That is, polyester A and polyester B according to the present invention are linear polyesters containing 85 mol% or more of ethylene terephthalate units, preferably 90 mol% or more, more preferably 95 mol% or more, particularly preferably 97 mol% or more. Including linear polyester.

Examples of the dicarboxylic acid used for copolymerization of the polyester include isophthalic acid, 2,6-naphthalenedicarboxylic acid, diphenyru 4,4'-dicarboxylic acid, diphenoxyethanedicarboxylic acid, 4,4'-diphenylsulfone dicarboxylic acid, Aromatic dicarboxylic acids such as 1,3-phenylene dioxydiacetic acid and functional derivatives thereof, oxyacids such as p-oxybenzoic acid and oxycaproic acid and functional derivatives thereof, adipic acid, sebacic acid, succinic acid, Examples thereof include aliphatic dicarboxylic acids such as glutaric acid and dimer acid and functional derivatives thereof, and alicyclic dicarboxylic acids such as hexahydroterephthalic acid, hexahydroisophthalic acid and cyclohexanedicarboxylic acid and functional derivatives thereof.
Examples of the glycol used for copolymerization of the polyester include aliphatic glycols such as diethylene glycol, trimethylene glycol, tetramethylene glycol, and neopentyl glycol, alicyclic glycols such as cyclohexanedimethanol, bisphenol A, and alkylene oxides of bisphenol A. Examples include aromatic glycols such as adducts.

  Furthermore, examples of the other copolymer component composed of the polyfunctional compound in the polyester include trimellitic acid and pyromellitic acid as acidic components, and glycerin and pentaerythritol as glycol components. The amount of the above copolymerization component used must be such that the polyester remains substantially linear. Monofunctional compounds such as benzoic acid and naphthoic acid may be copolymerized.

  The polyester A and polyester B according to the present invention can basically be produced by a conventionally known melt polycondensation method or melt polycondensation method-solid phase polymerization method. The melt polycondensation reaction may be performed in one stage or may be performed in multiple stages. These may be comprised from a batch-type reaction apparatus, and may be comprised from the continuous-type reaction apparatus. The melt polycondensation step and the solid phase polymerization step may be operated continuously or may be operated separately. Hereinafter, an example of a preferable continuous production method for the polyester composition of the present invention will be described using polyethylene terephthalate (PET) as an example, but the present invention is not limited thereto. That is, a direct esterification method in which terephthalic acid is directly reacted with ethylene glycol and, if necessary, other copolymerization components to distill off water and esterify, followed by polycondensation under reduced pressure in the presence of a polycondensation catalyst, or , Produced by a transesterification method in which dimethyl terephthalate, ethylene glycol, and other copolymerization components as required are reacted to distill off methyl alcohol and transesterify, followed by polycondensation under reduced pressure in the presence of a polycondensation catalyst. Is done. Then, when the intrinsic viscosity is increased or the low acetaldehyde content or the low cyclic trimer content is used, such as a heat-resistant container for low flavor beverages or a film for inner surfaces of metal cans for beverages. The resulting melt polycondensed polyester is subsequently subjected to solid state polymerization.

  First, when producing a low polymer by esterification reaction, it is 1.02-2.0 mol with respect to 1 mol of terephthalic acid or its ester derivative, Preferably it is 1.03-1.5 mol, Preferably it is 1 A slurry containing 0.03 to 1.4 mol of ethylene glycol is prepared and continuously supplied to the esterification reaction step.

In the esterification reaction, water or alcohol produced by the reaction is removed out of the system by a rectification column under conditions where ethylene glycol is refluxed using a multistage apparatus in which at least two esterification reactors are connected in series. While implementing. The temperature of the first stage esterification reaction is 240 to 270 ° C., preferably 245 to 265 ° C., and the pressure is 0.2 to 3 kg / cm ² G, preferably 0.5 to ² kg / cm ² G. The temperature of the esterification reaction in the final stage is usually 250 to 280 ° C, preferably 255 to 275 ° C, and the pressure is usually 0 to 1.5 kg / cm ² G, preferably 0 to 1.3 kg / cm ² G. . When carried out in three or more stages, the reaction conditions for the esterification reaction in the intermediate stage are conditions between the reaction conditions for the first stage and the reaction conditions for the final stage. The increase in the reaction rate of these esterification reactions is preferably distributed smoothly at each stage. Ultimately, it is desirable that the esterification reaction rate reaches 90% or more, preferably 93% or more. By these esterification reactions, low-order condensates having a molecular weight of about 500 to 5,000 are obtained.

  When terephthalic acid is used as a raw material, the esterification reaction can be carried out without a catalyst by the catalytic action of terephthalic acid as an acid, but may be carried out in the presence of a polycondensation catalyst.

  Also, tertiary amines such as triethylamine, tri-n-butylamine, benzyldimethylamine, quaternary ammonium hydroxides such as tetraethylammonium hydroxide, tetra-n-butylammonium hydroxide, trimethylbenzylammonium hydroxide, and lithium carbonate When a small amount of a basic compound such as sodium carbonate, potassium carbonate or sodium acetate is added, the proportion of dioxyethylene terephthalate component units in the main chain of polyethylene terephthalate is relatively low (5% relative to all diol components). Mol% or less).

  Next, in the case of producing a low polymer by transesterification, 1.1 to 2.0 mol, preferably 1.2 to 1.5 mol of ethylene glycol was contained with respect to 1 mol of dimethyl terephthalate. The solution is prepared and continuously fed to the transesterification step.

  The transesterification reaction is carried out while removing methanol generated by the reaction outside the system using a rectification column under the condition that ethylene glycol is distilled back using an apparatus in which 1 to 2 transesterification reactors are connected in series. To do. The temperature of the first stage transesterification is 180 to 250 ° C, preferably 200 to 240 ° C. The temperature of the transesterification reaction in the final stage is usually 230 to 270 ° C., preferably 240 to 265 ° C., and as the transesterification catalyst, fatty acid salts such as Zn, Cd, Mg, Mn, Co, Ca, Ba, carbonates Alternatively, Pb, Zn, Sb, Ge oxide or the like is used. A low-order condensate having a molecular weight of about 200 to 500 is obtained by these transesterification reactions.

  Dimethyl terephthalate, terephthalic acid or ethylene glycol, which is the starting material, includes virgin dimethyl terephthalate derived from para-xylene, ethylene glycol derived from terephthalic acid or ethylene, as well as methanol decomposition from used PET bottles. A recovered raw material such as dimethyl terephthalate, terephthalic acid, bishydroxyethyl terephthalate or ethylene glycol recovered by a chemical recycling method such as decomposition of ethylene glycol or ethylene glycol can also be used as at least part of the starting material. Needless to say, the quality of the recovered raw material must be refined to a purity and quality suitable for the intended use.

  Subsequently, the obtained low-order condensate is supplied to a multistage liquid phase condensation polymerization process. The polycondensation reaction conditions are as follows: the first stage polycondensation reaction temperature is 250 to 290 ° C., preferably 260 to 280 ° C., and the pressure is 500 to 20 Torr, preferably 200 to 30 Torr. The temperature is 265 to 300 ° C., preferably 275 to 295 ° C., and the pressure is 10 to 0.1 Torr, preferably 5 to 0.5 Torr. When carried out in three or more stages, the reaction conditions for the intermediate stage polycondensation reaction are conditions between the reaction conditions for the first stage and the reaction conditions for the last stage. The degree of increase in intrinsic viscosity achieved in each of these polycondensation reaction steps is preferably distributed smoothly. A single-stage polycondensation apparatus may be used for the polycondensation reaction.

  The polycondensation reaction is performed using a polycondensation catalyst. As the polycondensation catalyst, at least one compound selected from Ge, Sb, Ti, or Al compounds is preferably used. These compounds are added to the reaction system as powders, aqueous solutions, ethylene glycol solutions, ethylene glycol slurries and the like.

  Examples of the Ge compound include amorphous germanium dioxide, crystalline germanium dioxide powder or ethylene glycol slurry, a solution obtained by heating and dissolving crystalline germanium dioxide in water, or a solution obtained by adding ethylene glycol to this and heat treatment. In particular, in order to obtain the polyester used in the present invention, it is preferable to use a solution in which germanium dioxide is dissolved by heating in water, or a solution in which ethylene glycol is added and heated. In addition, compounds such as germanium tetroxide, germanium hydroxide, germanium oxalate, germanium chloride, germanium tetraethoxide, germanium tetra-n-butoxide, and germanium phosphite can also be used. These polycondensation catalysts can be added during the esterification step. When a Ge compound is used, the amount used is preferably 10 to 150 ppm, more preferably 13 to 100 ppm, and still more preferably 15 to 70 ppm as the residual amount of Ge in the polyester.

  Examples of Ti compounds include tetraalkyl titanates such as tetraethyl titanate, tetraisopropyl titanate, tetra-n-propyl titanate, tetra-n-butyl titanate, and partial hydrolysates thereof, titanium acetate, titanyl oxalate, titanyl oxalate, titanyl oxalate Sodium, titanyl oxalate, titanyl calcium oxalate, titanyl oxalate compounds such as titanium strontium oxalate, titanium trimellitate, titanium sulfate, titanium chloride, titanium halide hydrolyzate, titanium oxalate, titanium fluoride, titanium hexafluoride Titanium with potassium acid, ammonium hexafluorotitanate, cobalt hexafluorotitanate, manganese hexafluorotitanate, titanium acetylacetonate, hydroxy polyvalent carboxylic acid or nitrogen-containing polyvalent carboxylic acid Complex compound, a complex oxide of titanium and silicon or zirconium, a reaction product of titanium alkoxide and the phosphorus compound. The Ti compound is added so that the remaining amount of Ti in the produced polymer is in the range of 0.1 to 50 ppm.

  Examples of the Sb compound include antimony trioxide, antimony acetate, antimony tartrate, antimony potassium tartrate, antimony oxychloride, antimony glycolate, antimony pentoxide, and triphenylantimony. The Sb compound is added so that the residual amount of Sb in the produced polymer is preferably in the range of 50 to 250 ppm.

  Al compounds include aluminum acetate, basic aluminum acetate, aluminum chloride, aluminum hydroxide, aluminum hydroxide chloride, aluminum carbonate, aluminum phosphate, aluminum phosphonate and other inorganic acid salts, aluminum n-propoxide, aluminum iso-propoxide Aluminum alkoxides such as aluminum n-butoxide and aluminum t-butoxide, aluminum chelate compounds such as aluminum acetylacetonate, aluminum acetylacetate, aluminum ethylacetoacetate, aluminum ethylacetoacetate diiso-propoxide, trimethylaluminum, triethylaluminum, etc. Organic aluminum compounds and partial hydrolysates thereof, aluminum oxide, etc. It is. Of these, aluminum acetate, basic aluminum acetate, aluminum chloride, aluminum hydroxide, aluminum hydroxide chloride and aluminum acetylacetonate are particularly preferred. The Al compound is added so that the remaining amount of Al in the produced polymer is in the range of 5 to 200 ppm.

  In the production of polyester A and polyester B according to the present invention, an alkali metal compound or an alkaline earth metal compound may be used in combination as necessary. The alkali metal or alkaline earth metal is preferably at least one selected from Li, Na, K, Rb, Cs, Be, Mg, Ca, Sr, and Ba, and the use of an alkali metal or a compound thereof is preferable. More preferred. When using an alkali metal or a compound thereof, use of Li, Na, K is particularly preferable. Examples of the alkali metal and alkaline earth metal compounds include saturated aliphatic carboxylates such as formic acid, acetic acid, propionic acid, butyric acid, and succinic acid, and unsaturated aliphatic carboxylates such as acrylic acid and methacrylic acid. , Aromatic carboxylates such as benzoic acid, halogen-containing carboxylates such as trichloroacetic acid, hydroxycarboxylates such as lactic acid, citric acid and salicylic acid, carbonic acid, sulfuric acid, nitric acid, phosphoric acid, phosphonic acid, hydrogen carbonate, phosphorus Inorganic acid salts such as acid hydrogen, hydrogen sulfide, sulfurous acid, thiosulfuric acid, hydrochloric acid, hydrobromic acid, chloric acid and bromic acid, and organic sulfonates such as 1-propanesulfonic acid, 1-pentanesulfonic acid and naphthalenesulfonic acid , Organic sulfates such as lauryl sulfate, methoxy, ethoxy, n-propoxy, iso-propoxy, n-butoxy, tert-butyl Alkoxides such as alkoxy, chelate compounds and the like acetylacetonate, hydrides, oxides, and hydroxides and the like.

  The alkali metal compound or alkaline earth metal compound is added to the reaction system as a powder, an aqueous solution, an ethylene glycol solution, or the like. The alkali metal compound or alkaline earth metal compound is added so that the residual amount of these elements in the produced polymer is in the range of 1 to 50 ppm.

  Furthermore, polyester A and polyester B according to the present invention were selected from the group consisting of silicon, manganese, iron, cobalt, zinc, gallium, strontium, zirconium, niobium, molybdenum, indium, tin, hafnium, thallium, tungsten. A metal compound containing at least one element may be contained. These metal compounds include saturated aliphatic carboxylates such as acetates of these elements, unsaturated aliphatic carboxylates such as acrylates, aromatic carboxylates such as benzoic acid, and halogens such as trichloroacetic acid. Hydroxycarboxylates such as carboxylates and lactates, inorganic acid salts such as carbonates, organic sulfonates such as 1-propanesulfonate, organic sulfates such as lauryl sulfate, oxides, hydroxides, chlorides Products, alkoxides, acetylacetonates, and the like, and are added to the reaction system as powders, aqueous solutions, ethylene glycol solutions, ethylene glycol slurries, and the like. These metal compounds are added so that the residual amount of elements of these metal compounds per 1 ton of produced polymer is in the range of 0.05 to 3.0 mol. These metal compounds can be added at any stage of the polyester formation reaction step.

  Also, as stabilizers, phosphoric acid, phosphoric acid esters such as polyphosphoric acid and trimethyl phosphate, phosphonic acid compounds, phosphinic acid compounds, phosphine oxide compounds, phosphonous acid compounds, phosphinic acid compounds, phosphine compounds It is preferable to use at least one phosphorus compound selected from the group consisting of: Specific examples include phosphoric acid, phosphoric acid trimethyl ester, phosphoric acid triethyl ester, phosphoric acid tributyl ester, phosphoric acid triphenyl ester, phosphoric acid monomethyl ester, phosphoric acid dimethyl ester, phosphoric acid monobutyl ester, phosphoric acid dibutyl ester, Phosphoric acid, phosphorous acid trimethyl ester, phosphorous acid triethyl ester, phosphorous acid tributyl ester, methylphosphonic acid, methylphosphonic acid dimethyl ester, ethylphosphonic acid dimethyl ester, phenylphosphonic acid dimethyl ester, phenylphosphonic acid diethyl ester, phenylphosphonic acid Diphenyl ester and the like. These stabilizers can be added during the esterification reaction step from a slurry preparation tank of terephthalic acid and ethylene glycol. The P compound is added so that the residual amount of P in the produced polymer is preferably in the range of 5 to 100 ppm.

  When an Al compound is used as the polycondensation catalyst, it is preferably used in combination with a phosphorus compound, and is preferably used as a solution or slurry in which an aluminum compound and a phosphorus compound are previously mixed in a solvent. In the case of an Al compound, a more preferable phosphorus compound is at least one selected from the group consisting of phosphonic acid compounds, phosphinic acid compounds, phosphine oxide compounds, phosphonous acid compounds, phosphinic acid compounds, and phosphine compounds. It is a phosphorus compound. By using these phosphorus compounds, an effect of improving the catalytic activity is seen, and an effect of improving physical properties such as thermal stability of the polyester is seen. Among these, use of a phosphonic acid compound is preferable because of its great effect of improving physical properties and improving catalytic activity. Among the above-described phosphorus compounds, the use of a compound having an aromatic ring structure is preferable because the physical property improving effect and the catalytic activity improving effect are great.

  The melt polycondensation polyester obtained as described above is, for example, a method in which the melt polyester is extruded into water from the die pores after completion of the melt polycondensation and cut in water, or after the melt polycondensation is finished in the air from the die pores. After being extruded into strands, the chips are formed by a method of forming chips while cooling with cooling water.

  Next, the previous melt polycondensed polyester chip is preferably pre-crystallized in a continuous crystallization apparatus having two or more stages in an inert gas atmosphere. For example, in the case of PET, the temperature of 100 to 180 ° C. is 1 minute to 5 hours in the first stage precrystallization, and then the temperature of 160 to 210 ° C. is 1 minute to 3 hours in the second stage precrystallization. In the pre-crystallization of the second and higher stages, it is preferable to perform crystallization step by step at a temperature of 180 to 210 ° C. for 1 minute to 3 hours. The crystallinity of the chip after crystallization is preferably in the range of 30 to 65%, preferably 35 to 63%, and more preferably 40 to 60%. The crystallinity can be obtained from the density of the chip.

  Next, solid phase polymerization is carried out in an inert gas atmosphere or under reduced pressure at an optimum temperature for the prepolymer so that the increase in intrinsic viscosity due to solid phase polymerization is 0.10 deciliter / gram or more. For example, in the case of PET, the upper limit of the solid phase polymerization temperature is preferably 215 ° C. or lower, more preferably 210 ° C. or lower, particularly 208 ° C. or lower, and the lower limit is 190 ° C. or higher, preferably 195 ° C. or higher. is there.

  It is preferable to set the chip temperature to about 70 ° C. or less, preferably 60 ° C. or less, more preferably 50 ° C. or less within about 30 minutes, preferably within 20 minutes, more preferably within 10 minutes after completion of the solid phase polymerization.

  Moreover, as polyolefin resin mix | blended with the polyester composition of this invention, polyethylene-type resin, polypropylene-type resin, or alpha-olefin type resin is mentioned. These resins may be crystalline or amorphous.

  Examples of the polyethylene resin blended in the polyester composition of the present invention include ethylene homopolymer, ethylene, propylene, butene-1, 3-methylbutene-1, pentene-1, 4-methylpentene-1, Unsaturation such as other α-olefins having about 2 to 20 carbon atoms such as hexene-1, octene-1, and decene-1, and vinyl acetate, vinyl chloride, acrylic acid, methacrylic acid, acrylic ester, and methacrylic ester Examples thereof include derivatives of unsaturated carboxylic acids such as carboxylic acid and maleic anhydride, and copolymers with vinyl compounds such as styrene hydrocarbons and unsaturated epoxy compounds. Specifically, for example, ultra-low / low / medium / high-density polyethylene (branched or linear) ethylene homopolymer, ethylene-propylene copolymer, ethylene-butene-1 copolymer, ethylene- 4-methylpentene-1 copolymer, ethylene-hexene-1 copolymer, ethylene-octene-1 copolymer, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer Examples thereof include ethylene resins such as coalescence and ethylene-ethyl acrylate copolymer.

  Moreover, as a polypropylene resin mix | blended with the polyester composition of this invention, the homopolymer of propylene, propylene, ethylene, butene-1, 3-methylbutene-1, pentene-1, 4-methylpentene-1 is mentioned, for example. , Other α-olefins having about 2 to 20 carbon atoms such as hexene-1, octene-1, decene-1, vinyl acetate, vinyl chloride, acrylic acid, methacrylic acid, acrylic ester, methacrylic ester, styrene, etc. Or a copolymer with a diene such as hexadiene, octadiene, decadiene or dicyclopentadiene. Specific examples include propylene-based resins such as propylene homopolymer (atactic, isotactic, syndiotactic polypropylene), propylene-ethylene copolymer, propylene-ethylene-butene-1 copolymer.

The α-olefin resin to be blended in the polyester composition of the present invention includes homopolymers of α-olefins having about 2 to 8 carbon atoms such as 4-methylpentene-1, such α-olefins, and ethylene. , Copolymers with other α-olefins having about 2 to 20 carbon atoms such as propylene, butene-1,3-methylbutene-1, pentene-1, hexene-1, octene-1, and decene-1. It is done. Specifically, for example, butene-1 homopolymers, 4-methylpentene-1 homopolymers, butene-1-ethylene copolymers, butene-1-propylene copolymers, etc. - methylpentene-1 and C ₂ -C ₁₈ copolymer of α- olefins, and the like.

  Examples of the polyamide resin blended in the polyester composition of the present invention include lactam polymers such as butyrolactam, δ-valerolactam, ε-caprolactam, enantolactam, ω-laurolactam, 6-aminocaproic acid, 11 -Polymers of aminocarboxylic acids such as aminoundecanoic acid and 12-aminododecanoic acid, hexamethylenediamine, nonamethylenediamine, decamethylenediamine, dodecamethylenediamine, undecamethylenediamine, 2,2,4- or 2,4 Aliphatic diamines such as 1,4-trimethylhexamethylenediamine, alicyclic diamines such as 1,3- or 1,4-bis (aminomethyl) cyclohexane, bis (p-aminocyclohexylmethane), m- or p-xyl Diamine units such as aromatic diamines such as range amines and Polycondensates with aliphatic dicarboxylic acids such as glutaric acid, adipic acid, suberic acid and sebacic acid, alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid, and dicarboxylic acid units such as aromatic dicarboxylic acids such as terephthalic acid and isophthalic acid , And copolymers thereof, specifically, for example, nylon 4, nylon 6, nylon 7, nylon 8, nylon 9, nylon 11, nylon 12, nylon 66, nylon 69, nylon 610, nylon 611, nylon 612, nylon 6T, nylon 6I, nylon MXD6, nylon 6 / MXD6, nylon MXD6 / MXDI, nylon 6/66, nylon 6/610, nylon 6/12, nylon 6 / 6T, nylon 6I / 6T, etc. Can be mentioned. These resins may be crystalline or amorphous.

Moreover, as a polyacetal resin mix | blended with the polyester composition of this invention, a polyacetal homopolymer and a copolymer are mentioned, for example. The polyacetal homopolymer has a density measured by ASTM-D792 of 1.40 to 1.42 g / cm ³ and a melt flow ratio of 190 ° C. and a load of 2160 g measured by ASTM D-1238. A polyacetal having an (MFR) in the range of 0.5 to 50 g / 10 min is preferred.

As the polyacetal copolymer, the density measured by ASTM-D792 is 1.38 to 1.43 g / cm ³ , and the melt is measured at 190 ° C. and load is 2160 g by ASTMD-1238. Polyacetal copolymers having a flow ratio (MFR) in the range of 0.4 to 50 g / 10 min are preferred. Examples of these copolymer components include ethylene oxide and cyclic ether.

  In the production of the polyester composition containing the polyolefin resin or the like in the present invention, the polyester A and / or polyester B, or the polyester composition comprising the resin, such as the polyolefin resin, the content of the polyester composition is within the above range. In addition to a conventional method such as a method of directly adding and melt-kneading so as to be, or a method of adding and melt-kneading as a master batch, the resin is produced in the production stage of the polyester A and / or polyester B, for example, melting At any stage of polycondensation, immediately after melt polycondensation, immediately after precrystallization, at the time of solid-phase polymerization, immediately after solid-phase polymerization, or at the stage from the end of the production stage to the molding stage, etc. It can be added directly as a granule, or it can be a polyester A chip and / or a polyester B chip. Or can be a polyester composition comprising these methods is mixed by a method such as to be in contact with the resin member on flow conditions or after said contacting process, by a method in which melt kneading.

  Here, as a method of bringing the polyester chip into contact with the resin member under flow conditions, it is preferable that the polyester chip is brought into collision contact with the member within the space where the resin member is present. For example, immediately after the melt polycondensation of polyester, immediately after precrystallization, immediately after solid-phase polymerization, etc., at the time of filling and discharging the transport container in the transport stage as a product of polyester chips, etc. When the molding machine is inserted in the chip molding stage, a part of pneumatic transportation piping, gravity transportation piping, silo, magnet catcher magnet part, etc. is made of the resin, or the resin film, sheet, molded body, etc. Or lining the resin, or installing the resin member such as a rod-like or net-like body in the transfer path To include a method of transferring the polyester chips. The contact time of the polyester chip with the member is usually an extremely short time of about 0.01 seconds to several minutes, but a small amount of the resin can be mixed into the polyester.

  Polyester A and polyester B according to the present invention can be produced by appropriately controlling the type and amount of polycondensation catalyst, melt polycondensation, solid phase polymerization conditions, and the like. It can also be obtained by a method of giving an impact to the polyester chip thus obtained, and a method of blending a polyolefin resin, particularly polyethylene, polyamide resin, polyoxymethylene resin, etc. as described above.

  The chip shape of polyester A and polyester B may be any of a cylinder shape, a square shape, a spherical shape, a flat plate shape, and the like. The average particle diameter is usually 1.0 to 4 mm, preferably 1.0 to 3.5 mm, and more preferably 1.0 to 3.0 mm. For example, in the case of a cylinder type, it is practical that the length is about 1.0 to 4 mm and the diameter is about 1.0 to 4 mm. In the case of spherical particles, it is practical that the maximum particle size is 1.1 to 2.0 times the average particle size and the minimum particle size is 0.7 times or more the average particle size. The weight of the chip is practically in the range of 5 to 40 mg / piece. In addition, when it is necessary to improve the solid-phase polymerization rate or to reduce the content of aldehydes more effectively, the average weight of the chips is preferably 1 to 5 mg / piece.

  The content of the cyclic trimer of the polyester composition of the present invention is preferably 0.60% by weight or less, more preferably 0.50% by weight or less, and particularly preferably 0.35% by weight or less. The lower limit of the cyclic trimer content is 0.20% by weight or more, preferably 0.22% by weight or more, and more preferably 0.25% by weight or more from the viewpoint of economical production. In the case of molding a heat-resistant hollow molded article or the like from the polyester composition of the present invention, heat treatment is performed in a heating mold, but when the cyclic trimer content is 0.70% by weight or more, The adhesion of the oligomer to the surface of the heating mold increases rapidly, and the transparency of the obtained hollow molded article is very deteriorated.

  Further, the increase amount of the cyclic trimer when the polyester composition of the present invention is melted at a temperature of 290 ° C. for 60 minutes is preferably 0.3% by weight or less, more preferably 0.1% by weight or less. Is preferred. If the amount of cyclic trimer increased after melting at 290 ° C for 60 minutes exceeds 0.40% by weight, the amount of cyclic trimer will increase when the resin is melted and the oligomer will adhere to the surface of the heated mold. Increases rapidly, and the transparency of the obtained hollow molded article or the like is extremely deteriorated.

  The polyester composition of the present invention, in which the increase amount of the cyclic ester oligomer when melted at a temperature of 290 ° C. for 60 minutes is 0.40% by weight or less, deactivates at least one polycondensation catalyst of polyester A and polyester B. It can be manufactured by processing.

  Examples of the method of deactivating the polyester polycondensation catalyst include a method of contacting the polyester chip with water, water vapor or water vapor-containing gas.

  Examples of the hot water treatment method include a method in which polyester A, polyester B, or a polyester composition containing these as a main component is immersed in water, a method in which water is applied to these chips in a shower, and the like. The treatment time is 5 minutes to 2 days, preferably 10 minutes to 1 day, more preferably 30 minutes to 10 hours, and the water temperature is 20 to 180 ° C., preferably 40 to 150 ° C., more preferably 50 to 120 ° C.

  When the polyester chip is contacted with water vapor or water vapor containing gas, the water vapor or water vapor containing gas or water containing air at a temperature of 50 to 150 ° C., preferably 50 to 110 ° C., is preferably used per 1 kg of the granular polyester. The water vapor is supplied as water vapor in an amount of 0.5 g or more, or is present to bring the granular polyester into contact with water vapor. The contact between the polyester chip and water vapor is usually performed for 10 minutes to 2 days, preferably 20 minutes to 10 hours. The processing method may be either a continuous method or a batch method.

  Further, as another means for deactivating the polycondensation catalyst, there is a method in which a phosphorus compound is blended with the polyester and mixed and reacted in a molten state such as during molding to deactivate the polycondensation catalyst.

  As a method of blending a phosphorous compound with polyester, a predetermined amount of phosphorous compound is polyester by a method of dry blending the phosphorous compound with the polyester or a method of mixing a polyester masterbatch chip in which a phosphorous compound is melt-kneaded and blended with a polyester chip. And a method of inactivating the polycondensation catalyst by melting in an extruder or a molding machine, a method of immersing chips in a phosphorus compound solution, particularly a phosphoric acid aqueous solution, and a method of adding as a master batch. These phosphorus compounds may be copolymerized with polyester.

  Examples of the phosphorus compound used include phosphoric acid, phosphorous acid, phosphonic acid, and derivatives thereof. Specific examples thereof are the compounds described above, and these may be used alone or in combination of two or more.

  The polyester composition of the present invention can be obtained by mixing the polyester A and the polyester B by a conventionally known method. For example, the above polyester A and the above polyester B are dry blended with a tumbler, V-type blender, Henschel mixer, etc., and the dry blended mixture is melted once or more with a single screw extruder, twin screw extruder, kneader or the like. The method of mixing etc. is mentioned.

  When the polyester composition of the present invention is to be obtained by dry blending the polyester A chip and the polyester B chip by the method as described above, if the variation of the mixing ratio of both is large, the molding comprising the polyester composition Variations in the intrinsic viscosity of the body, crystallization characteristics, and the like occur. For this reason, characteristics such as acetaldehyde content, transparency, and thickness of the obtained molded body fluctuate and become a big problem. In addition, when the polyester composition after dry blending is supplied to a dryer or molding machine, or discharged from these devices, or when the polyester composition is transferred in a transfer pipe by a gas, etc. When moving the polyester, the blending ratio of polyester A or polyester B may vary. The variation factors include the difference in true density and bulk density between the two chips. The true density is mainly determined by the difference in the solid-state polymerization conditions such as the solid-phase polymerization temperature and time. It depends on the shape of the chip (the state of the cut end) and the amount of fine powder (also called fine) or fine particles.

  The density of the polyester A chips and the polyester B chips according to the present invention is preferably 1.392 grams / cubic centimeter or more, more preferably 1.393 grams / cubic centimeter or more. Further, the upper limit of the chip density is about 1.415 g / cubic centimeter, and when trying to obtain a chip having a density higher than this, there is a problem that chip fusion occurs during solid phase polymerization or in the solid phase polymerization process. The polymerization time becomes very long, causing problems in terms of economy, which is not preferable. Further, when the density of the chips is less than 1.390 grams / cubic centimeter, the content of the cyclic trimer cannot be reduced to 0.7% by weight or less, and problems such as mold contamination occur, which is not preferable.

  The difference in density between the polyester A chip and the polyester B chip according to the present invention is preferably within 0.02 gram / cubic centimeter, more preferably within 0.01 gram / cubic centimeter. When the difference in density exceeds 0.025 g / cubic centimeter, when the molded product is produced from the polyester composition, the variation of the blend ratio in the time series direction becomes large, so that the intrinsic viscosity and crystallization of the molded product are increased. Variations in characteristics occur, resulting in a molded product having large thickness spots, stretch spots, and transparent spots, which is a problem. The lower limit of the chip density difference is 0.001 gram / cubic centimeter.

  Further, the fines described below are highly likely to be highly crystallized than the chip. Thus, the fines contained in high density polyester chips with a density difference of more than 0.025 grams / cubic centimeter are suitable for the polyester compositions of the present invention (this is a polyester with a single intrinsic viscosity). The temperature is several degrees to about 10 ° C. lower than the optimum resin temperature for molding the resin), and remains as an unmelted or incomplete melt. This is a problem because it becomes whitened or cocoonous in the body and the commercial value is lost.

  The chip sizes of the polyester A and the polyester B according to the present invention are as described above. Among them, a suitable chip has a bulk density of 0.80 to 0.97 grams / cubic centimeter, preferably 0.8. 82-0.96 grams / cubic centimeter, particularly preferably 0.83-0.95 grams / cubic centimeter. When the bulk density is less than 0.80 grams / cubic centimeter, the flowability of the chips in the molding machine is poor and the mixing of the two becomes insufficient. Producing chips exceeding 0.97 grams / cubic centimeter is wasteful from an economic point of view. The difference in bulk density between the two is within 0.10 gram / cubic centimeter, preferably within 0.08 gram / cubic centimeter, more preferably within 0.05 gram / cubic centimeter, and particularly preferably within 0.03 gram / cubic centimeter. . When the difference in bulk density exceeds 0.10 gram / cubic centimeter, when the molded product is produced from the polyester composition, the variation of the blending ratio in the time-series direction becomes large. As a result, fluctuations in the crystallization characteristics occur, resulting in a molded product having large thickness spots, stretch spots, and transparent spots. The lower limit of the difference in bulk density of the chips is 0.005 grams / cubic centimeter.

  Moreover, it is preferable that the polyester composition of this invention contains 0.1-5000 ppm of fine of the same composition as the said polyester A or B. The fine content is preferably 0.1 to 3000 ppm, more preferably 0.1 to 1000 ppm, further preferably 0.1 to 500 ppm, and most preferably 0.1 to 100 ppm. When the content of fine is less than 0.1 ppm, the crystallization rate becomes very slow, and the crystallization of the plug portion of the hollow molded container becomes insufficient, so that the shrinkage amount of the plug portion is within the specified value range. It is difficult to capping, and it becomes impossible to capping, and the heat-fixed mold for molding heat-resistant hollow molded containers is so dirty that if you try to obtain a transparent hollow molded container, you must clean the mold frequently. It may not be possible. When the content exceeds 5000 ppm, the variation in blending amount and blending amount of the polyester A and the polyester B is likely to occur, and as a result, the intrinsic viscosity variation of the molded body becomes large, and the crystallization speed and stretchability vary. Arise. In the case of a sheet-like material, the transparency and the surface state are deteriorated, and the fluctuation of these characteristics is large. When this is stretched, the thickness unevenness is deteriorated. In addition, the degree of crystallinity of the plug part of the hollow molded body becomes excessive and fluctuates, and therefore the shrinkage amount of the plug part does not fall within the specified value range, resulting in poor capping of the plug part and leakage of contents. In addition, the preform for the hollow molded body is whitened, so that normal stretching is impossible. In particular, the fine content of the polyester composition for the hollow molded body is preferably 0.1 to 500 ppm.

  Similarly, the fine content of polyester A and polyester B constituting the polyester composition of the present invention is preferably 0.1 to 5000 ppm. The fine content is preferably 0.1 to 3000 ppm, more preferably 0.1 to 1000 ppm, further preferably 0.1 to 500 ppm, and most preferably 0.1 to 100 ppm. When it exceeds 5000 ppm, the bulk density is less than 0.80 grams / cubic centimeter, which is not preferable as described above.

  In addition, the fine melting point in the polyester composition of the present invention is preferably 263 ° C. or lower, more preferably 260 ° C. or lower. In the case of containing fines having a melting point exceeding 265 ° C., there is a possibility that crystals are not completely melted even under normal melt molding conditions of a single intrinsic viscosity polyester, and remain as crystal nuclei. This tendency becomes prominent at the time of molding at a lower resin temperature, which is optimal for the polyester composition, and greatly affects the appearance and crystallinity of the polyester unstretched molded article. In the case of a stretched hollow molded body, the crystallization speed is increased when the unstretched preformed body plug portion is heated, so that the crystallization of the plug portion becomes excessive. As a result, since the amount of shrinkage of the plug portion does not fall within the specified value range, the capping portion of the plug portion becomes defective and the contents may leak. In addition, the preform for hollow molding is whitened, so that normal stretching is impossible, thickness unevenness occurs, the crystallization speed is high, and the transparency of the obtained hollow molded body is deteriorated. Fluctuations also become large. Further, since the obtained sheet-like material is poor in transparency and has a high crystallization rate, normal stretching is impossible, and only a stretched film having large thickness spots and poor transparency can be obtained.

  The melting point of the fine is measured by the following method using a differential scanning calorimeter (DSC), and the melting peak temperature representing the melting point of the fine is one or more melting peaks. In the present invention, when there is one melting peak, the peak temperature is indicated, and when there are a plurality of melting peaks, the highest temperature among the plurality of melting peaks is indicated. The melting peak temperature is referred to as “the highest peak temperature of the fine melting peak temperature”, and is referred to as “fine melting point” in the examples.

  When a hollow molding preform or sheet having good transparency and stretchability is to be obtained from a polyester composition containing fines having a melting peak temperature exceeding 265 ° C., 300 ° C. It must be melt molded at these high temperatures. However, at such a high temperature of 300 ° C. or higher, the thermal decomposition of the polyester becomes severe, and a large amount of by-products such as acetaldehyde and formaldehyde are generated. As a result, the flavor of the contents such as molded articles is great. It will have an effect. When the polyester composition of the present invention contains at least one resin selected from the group consisting of the following polyolefin resins, polyamide resins, and polyacetal resins, these resins are generally related to the present invention. Since the thermal stability is often inferior to that of polyester, as described above, in molding at a high temperature of 300 ° C. or higher, a large amount of by-products are generated due to thermal decomposition. It will have a greater effect on the flavor.

  Further, the difference between the crystallization temperature when the polyester A according to the present invention is lowered and the crystallization temperature when the temperature of the polyester B is lowered is within 20 ° C., preferably within 18 ° C., more preferably within 15 ° C., and particularly preferably 10 ° C. It is within ℃. When the difference in the crystallization temperature when the temperature falls is more than 20 ° C., the transparency of the obtained molded product becomes very poor, and the variation in transparency becomes large.

  The formaldehyde content of polyester A and polyester B according to the present invention is 7 ppm or less, preferably 5 ppm or less, more preferably 3 ppm or less, and even more preferably 2 ppm or less. When the formaldehyde content is 7 ppm or more, the flavor and odor of the contents such as a container molded from this polyester are deteriorated.

  The amount of diethylene glycol copolymerized in polyester A and polyester B according to the present invention is 1.3 to 5.0 mol%, preferably 1.5 to 4. mol% of the glycol component constituting the polyester. 5 mol%, More preferably, it is 1.8-4.0 mol%, More preferably, it is 2.0-3.0 mol%, Most preferably, it is 2.0-2.9 mol%. When the amount of diethylene glycol exceeds 5.0 mol%, the thermal stability is deteriorated, the decrease in molecular weight becomes large at the time of molding, and the increased amount of acetaldehyde content and formaldehyde content is unfavorable. On the other hand, when the diethylene glycol content is less than 1.5 mol%, the transparency of the obtained molded article is deteriorated.

  The polyester composition of the present invention can be preferably used as a hollow molded product, a tray, a packaging material such as a biaxially stretched film, a metal can coating film, a fiber containing a monofilament, and the like. Moreover, the polyester composition of this invention can be used also as 1 component layers, such as a multilayer molded object and a multilayer film.

  The polyester composition of the present invention can be used to form films, sheets, containers, and other packaging materials using a commonly used melt molding method. Moreover, it is possible to improve mechanical strength by extending | stretching the sheet-like material which consists of a polyester composition of this invention at least to a uniaxial direction. The stretched film composed of the polyester composition of the present invention is a sheet-like material obtained by injection molding or extrusion molding, and can be any one of uniaxial stretching, sequential biaxial stretching, and simultaneous biaxial stretching that are usually used for PET stretching. It is molded using a stretching method. Further, it can be formed into a cup shape or a tray shape by pressure forming or vacuum forming.

Below, the concrete manufacturing method about the various uses in the case of PET is demonstrated easily.
In producing a stretched film, the stretching temperature is usually 80 to 130 ° C. Stretching may be uniaxial or biaxial, but biaxial stretching is preferred from the viewpoint of film physical properties. In the case of uniaxial stretching, the stretching ratio is usually 1.1 to 10 times, preferably 1.5 to 8 times. In the case of biaxial stretching, the longitudinal and transverse directions are usually 1.1 to 8 times, respectively. Preferably, it may be performed in a range of 1.5 to 5 times. The vertical / horizontal magnification is usually 0.5 to 2, preferably 0.7 to 1.3. The obtained stretched film can be further heat-set to improve heat resistance and mechanical strength. The heat setting is usually performed under tension at 120 to 240 ° C., preferably 150 to 230 ° C., usually for several seconds to several hours, preferably several tens of seconds to several minutes.

  In producing a hollow molded body, a blow molded from the polyester composition of the present invention is stretch blow molded, and an apparatus conventionally used in blow molding of PET can be used. Specifically, for example, once a preform is formed by injection molding or extrusion molding, the plug part and the bottom part are processed as it is, and then reheated, and then biaxial stretch blow molding such as hot parison method or cold parison method The law applies. The molding temperature in this case, specifically, the temperature of each part of the cylinder of the molding machine and the nozzle is usually in the range of 260 to 300 ° C. The stretching temperature is usually 70 to 120 ° C., preferably 90 to 110 ° C., and the stretching ratio is usually 1.5 to 3.5 times in the longitudinal direction and 2 to 5 times in the circumferential direction. The obtained hollow molded body can be used as it is, but in particular in the case of beverages that require hot filling, such as fruit juice beverages and oolong teas, it is generally heat-set in a blow mold and heat resistant. Used to impart sex. The heat setting is usually performed at 100 to 200 ° C., preferably 120 to 180 ° C. for several seconds to several hours, preferably several seconds to several minutes, under tension by compressed air or the like.

  In addition, in order to impart heat resistance to the plug part, the plug part of the preform obtained by injection molding or extrusion molding is crystallized in a far-infrared or near-infrared heater installation oven, or after the bottle is formed, The stopper is crystallized with the heater.

  The polyester composition of the present invention can also be used for the production of a stretched hollow molded body by a so-called compression molding method in which a preform obtained by compression molding a melt mass cut after melt extrusion is stretch blow molded. Can do.

  From the polyester composition of the present invention, inferior products generated during the molding of hollow molded products and washed products of used collection containers from the market are mixed with virgin raw materials and reused in terms of transparency and heat resistance. It is possible to give a hollow molded body having no problem.

  In the polyester composition of the present invention, known ultraviolet absorbers, antioxidants, oxygen scavengers, lubricants added from the outside, lubricants precipitated internally during the reaction, mold release agents, nucleating agents, stability Various additives such as an agent, an antistatic agent, a bluing agent, a dye, and a pigment may be blended.

In addition, when the polyester composition of the present invention is used for a film, in order to improve handling properties such as slipping property, winding property, and blocking resistance, calcium carbonate, magnesium carbonate, barium carbonate, sulfuric acid are included in the polyester. Inorganic particles such as calcium, barium sulfate, lithium phosphate, calcium phosphate, magnesium phosphate, organic salt particles such as calcium oxalate, calcium, barium, zinc, manganese, magnesium, terephthalate, divinylbenzene, styrene, acrylic acid, Inactive particles such as crosslinked polymer particles such as methacrylic acid, acrylic acid, or a vinyl monomer of methacrylic acid, alone or as a copolymer can be contained.
The main characteristic value measuring methods in the present invention will be described below.

EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples.
The main characteristic value measurement methods will be described below.
The composition and characteristics of the polyester are measured after the chips are frozen and ground and mixed thoroughly.

(1) Intrinsic viscosity of polyester (IV)
It calculated | required from the solution viscosity at 30 degreeC in a 1,1,2,2-tetrachloroethane / phenol (2: 3 weight ratio) mixed solvent. The IV of the polyester composition was a weighted average value calculated from the IV of the constituent polyester.

(2) Polyethylene glycol content of polyester (hereinafter referred to as [DEG content])
Decomposition with methanol, the amount of DEG was quantified by gas chromatography, and expressed as a ratio (mol%) to the total glycol components.

(3) Polyester cyclic trimer content (hereinafter referred to as “CT content”)
300 mg of the frozen and ground sample is dissolved in 3 ml of a hexafluoroisopropanol / chloroform mixed solution (volume ratio = 2/3), and further diluted with 30 ml of chloroform. To this is added 15 ml of methanol to precipitate the polymer, followed by filtration. The filtrate was evaporated to dryness, brought to a constant volume with 10 ml of dimethylformamide, and the cyclic trimer was quantified by high performance liquid chromatography.

(4) Acetaldehyde content of polyester (hereinafter referred to as “AA content”) and AA increase amount before and after stepped molding (hereinafter referred to as “ΔAA amount”)
Sample / distilled water = 1 g / 2 cc of glass ampoule substituted with nitrogen was sealed and subjected to extraction treatment at 160 ° C for 2 hours. After cooling, acetaldehyde in the extract was measured by high-sensitivity gas chromatography. The concentration was expressed in ppm. In the case of a preform, a sample was taken from the mouth.
In addition, ΔAA amount is AA amount of 2 mm-thick stepped plate sample-AA amount of chip before molding, but in the case of molding a dry blend composition, the average value of AA amounts of individual polyesters Was the AA amount of the chip before molding.

(5) Increasing amount of cyclic trimer at the time of melting polyester (△ CT amount)
A sample was taken from the 3 mm thick plate molded in (11), dried under reduced pressure for about 16 hours at 140 ° C. and 0.1 mmHg or less, and then 3 g of the polyester sample was placed in a glass test tube and 290 ° C. under a nitrogen atmosphere. Soak in an oil bath for 60 minutes to melt. The amount of increase in cyclic trimer at the time of melting is determined by the following equation.
In addition, the cyclic trimer content before melting was a weighted average value of the cyclic trimer content of the polyester constituting the polyester composition.
Increase in cyclic trimer during melting (wt%) =
Cyclic trimer content after melting (wt%)-cyclic trimer content before melting (wt%)

(6) Measurement of Fine Content About 0.5 kg of resin, sieve (A) with a mesh size of 5.6 mm according to JIS-Z8801, and sieve with a mesh size of 1.7 mm (diameter) 20 cm) (B) was placed on a sieve combined in two stages, and sieved at 1800 rpm for 1 minute with a swing type sieve shaker SNF-7 manufactured by Terraoka. This operation was repeated and a total of 20 kg of resin was sieved. However, when the fine content is small, the amount of the sample is appropriately changed.
The fine sieved under the sieve (B) is washed with a 0.1% aqueous cationic surfactant solution, then washed with ion-exchanged water, and filtered through a G1 glass filter manufactured by Iwaki Glass Co., Ltd. It was. These were dried together with a glass filter in a dryer at 100 ° C. for 2 hours, then cooled and weighed. Again, the same operations of washing and drying with ion-exchanged water were repeated to confirm that the weight became constant, and the weight of the glass filter was subtracted from this weight to obtain the fine weight. The fine content is the fine weight / the total resin weight that has been sieved.

(7) Measurement of fine melting peak temperature (hereinafter referred to as “fine melting point”) Measured using a differential scanning calorimeter (DSC) manufactured by Seiko Denshi Kogyo Co., Ltd., RDC-220. All fines collected by the method of (6) were frozen and pulverized and mixed, then dried under reduced pressure at 25 ° C. for 3 days, and 4 mg of sample was used for one measurement at a rate of temperature increase of 20 ° C./min. DSC measurement is performed to determine the melting peak temperature on the highest temperature side of the melting peak temperature. The measurement is performed on a maximum of 10 samples, and the average value of the melting peak temperatures on the highest temperature side is obtained. If there is a single melting peak, the temperature is determined.

(8) Crystallization temperature (Tc1) when the molded body is heated and crystallization temperature (Tc2) when the temperature is lowered
Measured with a differential thermal analyzer (DSC), RDC-220, manufactured by Seiko Electronics Industry Co., Ltd. Using 10 mg of a sample from the center of a 2 mm thick plate of the molded plate of (11) below. The temperature was raised at a rate of temperature rise of 20 ° C./minute and held at 290 ° C. for 3 minutes, then the temperature was lowered from 290 ° C. to 240 ° C. at 10 ° C./minute, and further from 240 ° C. to 130 ° C. at 7 ° C./minute. The temperature dropped. The peak temperature of the crystallization peak observed at the time of temperature rise is defined as the crystallization temperature (Tc1) at the time of temperature increase, and the peak temperature of the crystallization peak observed at the time of temperature decrease is defined as the crystallization temperature at the time of temperature decrease.

(9) Density of polyester chip It was measured at 30 ° C. with a density gradient tube of calcium nitrate / water solution.

(10) Haze (degree of haze%) and haze spots A sample was cut from the molded product (thickness 5 mm) of the following (11) and measured with a Nippon Denshoku Co., Ltd. haze meter, model NDH2000. Moreover, the haze of the molded board (thickness 5 mm) shape | molded continuously 50 times was measured, and the haze spot was calculated | required by the following.
Haze spots = maximum value of haze / minimum value of haze

(11) Molding of Stepped Molding Plate The polyester dried under reduced pressure at 140 ° C. for about 16 hours using a vacuum dryer is shown in FIG. 1 and FIG. 2 by an injection molding machine M-150C-DM type injection molding machine manufactured by Meiki Seisakusho. 2 mm to 11 mm having a gate part (G) (A part thickness = 2 mm, B part thickness = 3 mm, C part thickness = 4 mm, D part thickness = 5 mm, E part thickness = 10 mm, F A stepped molded plate having a thickness of part thickness = 11 mm) was injection molded.

Polyester previously dried under reduced pressure using a vacuum dryer DP61 manufactured by Yamato Kagaku was used, and a dry inert gas (nitrogen gas) purge was performed in the molding material hopper to prevent moisture absorption during molding. The plasticizing conditions of the M-150C-DM injection molding machine are as follows: feed screw rotation speed = 70%, screw rotation speed = 120 rpm, back pressure 0.5 MPa, cylinder temperature 45 ° C., 250 ° C. from the bottom of the hopper in order, nozzle The temperature was set at 290 ° C. The injection conditions are 20% for injection speed and holding pressure, and the injection pressure and holding pressure are adjusted so that the weight of the molded product is 146 ± 0.2g. In this case, the holding pressure is 0.5MPa lower than the injection pressure. It was adjusted.
The upper limit of the injection time and pressure holding time is set to 10 seconds and 7 seconds, respectively, and the cooling time is set to 50 seconds. The total cycle time including the time for taking out the molded product is about 75 seconds.

Although the temperature of the mold is always controlled by introducing cooling water having a water temperature of 10 ° C., the mold surface temperature at the time of stable molding is around 22 ° C.
The test plate for evaluating the molded product characteristics was arbitrarily selected from the 11th to 18th shots of the stable molded product after the molding material was introduced and the resin was replaced.
A 2 mm-thick plate (part A in FIG. 1) measures AA increase (ΔAA amount), crystallization temperature during temperature rise (Tc1) and crystallization temperature during temperature drop (Tc2), and a plate with 3 mm thickness (FIG. 1). B part) is used for the measurement of the increase in cyclic trimer (ΔCT amount) during melting, and the 5 mm-thick plate (D part in FIG. 1) is used for haze (degree%) measurement.

(12) Molding of Hollow Molded Body The polyester was dried with a dryer using dehumidified air, and a preform was molded at a resin temperature of 290 ° C. with an M-150C-DM injection molding machine manufactured by Koki Seisakusho. The plug portion of this preform was heated and crystallized with a home-made plug portion crystallizer. Next, this preform was biaxially stretched and blown with a LB-01E molding machine manufactured by CORPOPLAST, and then heat-set in a mold set at about 150 ° C. for about 5 seconds to form a container having a capacity of 1500 cc. The stretching temperature was controlled at 100 ° C.

(13) Heat resistance of the hollow molded body The hollow molded body molded in (12) is allowed to stand for 1 week under conditions of room temperature and humidity of 90%, and then the hollow molded body is filled with hot water of 90 ° C. and sealed. After standing for 10 minutes, it was cooled with water, and the internal volume before and after filling was measured. It calculated | required from the internal volume before and behind filling with the following shrinkage rate.
The heat resistance was evaluated as follows from the value of shrinkage rate (%).
○: 0 ≦ shrinkage rate (%) <0.5
×: 0.5 ≦ Shrinkage rate (%)

Shrinkage rate (%) = 100 × (internal volume g before filling−internal volume g after filling) / internal volume g before filling

(14) Appearance of Hollow Molded Body 100 hollow molded bodies of the above (12) were visually observed and evaluated as follows.
◎: Transparent and no appearance problem △: 1 to 5 hollow moldings with whitened flow pattern or whitened product per 100 hollow molded products ×: Hollow with whitened flow pattern or whitened product per 100 hollow molded products 6 or more compacts

(15) Evaluation of leakage of contents from hollow molded body After filling the hollow molded body molded in the above (12) with hot water of 90 ° C, capping with a capping machine, the container is tilted and left to stand to leak the contents. Examined. The deformation state of the plug after capping was also examined.

(16) Bulk density of polyester Measured by a method according to JIS K6721.

(Polyester A)
High purity terephthalic acid and ethyl glycol are continuously supplied to the first esterification reactor containing the reactants in advance, and the average residence time is 3 hours at about 250 ° C. and 0.5 kg / cm ² G with stirring. Reaction was performed. This reaction product was sent to the second esterification reactor, and the reaction was carried out with stirring at about 260 ° C. and 0.05 kg / cm ² G to a predetermined reactivity. In addition, crystalline germanium dioxide is dissolved in water by heating, ethylene glycol is added thereto, and the heat-treated catalyst solution, ethylene glycol solution of phosphoric acid and ethylene glycol, and linear low density polyethylene (MI = About 0.9 g / 10 min, density = about 0.923 g / cm ³ ) was continuously fed separately to this second esterification reactor. The esterification reaction product is continuously sent to the first polymerization reactor under stirring at about 265 ° C. and 25 torr for 1 hour, then in the second polymerization reactor under stirring at about 265 ° C. and 3 torr for 1 hour, and further Polymerization was conducted at about 275 ° C. and 0.5 to 1 torr with stirring in the third polymerization reactor. The intrinsic viscosity (IV) of the obtained PET resin was 0.53.

  After fine removal of this resin, it was subsequently crystallized at about 155 ° C. in a nitrogen atmosphere, further preheated to about 200 ° C. in a nitrogen atmosphere, and then sent to a continuous solid-phase polymerization reactor for solid phase polymerization at about 207 ° C. in a nitrogen atmosphere. . After the solid-phase polymerization, the fine particles were removed by continuous treatment in the sieving step and the fine removal step.

The obtained PET has an intrinsic viscosity of 0.70 deciliter / gram, an acetaldehyde (AA) content of 3.0 ppm, a cyclic trimer content of 0.34% by weight, a density of 1.394 g / cm ³ and a bulk density. The amount of PE blended at 0.86 g / cm ³ was 5 ppb. The properties of the obtained PET are shown in Table-1.

(Polyester B, C, D)
Polyesters B, C, and D were obtained by reacting in the same manner as in Example 1 except that the polycondensation catalyst addition amount, the polyethylene addition amount, and the solid phase polymerization time were changed.
The properties of the obtained PET are shown in Table-1.

(Polyester E, F)
Each prepolymer was obtained by melt polycondensation in the same manner as in Example 1 except that the esterification conditions, the polycondensation catalyst addition amount, the polyethylene addition amount, and the chip size were changed.
The obtained prepolymer was put into a rotary reduced pressure solid phase polymerization apparatus without fine removal, and crystallized at 70 to 160 ° C. under reduced pressure while rotating, followed by solid phase polymerization at 210 ° C. Polyester F was subjected to solid phase polymerization with a longer solid phase polymerization time than polyester E, and fine or the like was not removed in the sieving step. The properties of the obtained PET are shown in Table-1.

Example 1
The above-mentioned polyester A and polyester B pellets were blended at a ratio of 7: 3, and evaluation was performed using a molded plate and a hollow molded container obtained by the methods (11) and (12). The results are shown in Table 2.
The amount of increase in AA (ΔAA amount) before and after molding is 9.9 ppm, the haze of the molded plate is 4.5%, and the haze spot of the molded plate is 0.2%, which is good for the heat resistance and content of the hollow molded container. There were no problems with leakage of materials, appearance of the hollow molded container, and the shape of the cap after capping.

(Examples 2 and 3)
The polyester compositions of Examples 2 and 3 were evaluated in the same manner according to the compositions shown in Table 2. The results are shown in Table 2.
All the evaluated characteristics were as good as in Example 1.

(Comparative Example 1)
The polyester composition of Comparative Example 1 was evaluated in the same manner according to the composition shown in Table 3.
Compared with Example 1, the ΔAA before and after the preform molding of Comparative Example 1 was clearly high, and some containers had leaked contents, which was not a satisfactory result. The results are shown in Table 3.

Similarly, the polyester compositions of Comparative Examples 2 and 3 were evaluated according to the compositions shown in Table 3.
Obviously, ΔAA, haze and haze spots were high as compared with the examples, and the heat resistance, contents leakage, appearance and shape of the plug after capping were also poor. The results are shown in Table 3.

Example 4
For the same composition as in Example 1, a stepped molded plate was molded in the same manner as in (11) except that the 290 ° C. portion was reduced to 280 ° C. at the cylinder temperature of the injection molding machine described in the method of (11). ,evaluated.
There was no problem with haze. The results are shown in Table 4.

(Comparative Example 4)
The non-water-treated product of polyester C was evaluated in the same manner as in Example 4.
Obviously, compared with Example 4, ΔAA and haze before and after molding of Comparative Example 1 were high. The results are shown in Table 4.

(Polyester G, H)
As the polycondensation catalyst, an ethylene glycol solution of basic aluminum acetate, Irganox 1222 (manufactured by Ciba Specialty Chemicals) and an ethylene glycol solution in which ethylene glycol is heated in advance, and the addition amount of the polyethylene is changed. Were reacted in the same manner as polyester A and polyester B to obtain polyesters G and H, respectively.
The properties of the obtained PET are shown in Table 5.

(Polyester I, J)
As a polycondensation catalyst, an ethylene glycol solution of titanium tetrabutoxide, an ethylene glycol solution of magnesium acetate tetrahydrate was used, and the polyester was reacted in the same manner as polyester A or polyester B except that the amount of polyethylene added was changed. I and J were obtained.
The properties of the obtained PET are shown in Table-5.

(Polyester K, L)
For the water treatment of the polyester chip, using the apparatus shown in FIG. 3, the raw material chip supply port (1) at the upper part of the treatment tank, the overflow discharge port (2) located at the upper limit level of the treatment water of the treatment tank, and the polyester at the lower part of the treatment tank Discharge port (3) for the mixture of chips and treated water, treated water discharged from this overflow discharge port, treated water discharged from the treatment tank, and draining device (4) discharged from the discharge port at the bottom of the treated tank The pipe (6) through which the treated water passing through the pipe is sent again to the water treatment tank via the fine powder removing device (5) whose filter medium is a paper-made continuous filter, and the inlet for these fine powder removed treated water (7) An adsorption tower (8) for adsorbing acetaldehyde in the treated water after fine powder removal, and a tower-type treatment tank having an internal capacity of about 50 m ³ equipped with a new ion exchange water inlet (9) were used.

After removing the fine and film-like materials from the polyester A or polyester B chip by the airflow classification process and the vibration sieving process, the speed is 50 kg / hour into a water treatment tank controlled at a treatment water temperature of 95 ° C. Then, the water was continuously fed from the supply port (1) at the upper part of the treatment tank, and the PET chip was continuously extracted from the discharge port (3) at the lower part of the treatment tank together with the treated water at a rate of 50 kg / hour. In the introduced water collected in front of the ion exchange water inlet (9) of the treatment apparatus, the particle content of 1 to 25 μm in particle size is about 1900/10 ml, the sodium content is 0.05 ppm, and the magnesium content is 0.1. 10 ppm, calcium content is 0.08 ppm, silicon content is 0.17 ppm, and the number of particles having a particle size of 1 to 40 μm of recycled water after treatment in the filtration device (5) and the adsorption tower (8) is about 10,000. Pieces / 10 ml.
After the water treatment, fines and the like were removed in the vibration sieve process and the airflow classification process.
The properties of the obtained PET (Polyester K and Polyester L) are shown in Table 5.

(Examples 5 and 6)
The polyester compositions of Examples 5 and 6 were evaluated in the same manner with the compositions shown in Table 6.
The results are shown in Table 6.
All the evaluated characteristics were as good as in Example 1.

(Example 7)
Evaluation was similarly performed about the polyester composition of the composition shown in Table 6, which was treated with hot water.
The results are shown in Table 6.
The amount of increase in cyclic trimer of (5) is as low as 0.11% by weight, and the amount of increase in AA before and after forming the stepped molded plate is as low as 7.0 ppm. Other characteristics are the same as in Example 1. It was good.

The present invention provides a polyester composition that provides a molded product that has a small amount of aldehyde generated during molding due to improved flow characteristics and that has excellent mechanical properties such as pressure resistance when formed into a molded product. In addition, since the polyester composition of the present invention has improved flow characteristics, there is little distortion during molding, and a molded article having excellent heat-resistant dimensional stability, particularly a hollow molded article, can be efficiently produced by high-speed molding, and The present invention provides a polyester composition excellent in pressure resistance and heat resistance, excellent in long-time continuous moldability that does not contaminate the mold, and a molded article comprising the same.
The polyester composition of the present invention can meet high quality requirements in the field of containers, sheets and the like.

Plan view of stepped plate Side view of stepped plate Schematic diagram of water treatment equipment

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Raw material chip supply port 2 Overflow discharge port 3 Drain port of polyester chip and treated water 4 Drainage device 5 Fine removal device 6 Pipe 7 Recycled water and / or ion exchange water introduction port 8 Adsorption tower 9 Ion exchange water introduction port

Claims (9)

A polyester composition comprising, as a main component, the following polyester A and polyester B having ethylene terephthalate as a main repeating unit, and the blending ratio of polyester A and polyester B is 95/5 to 5/95 by weight ratio, The difference between the intrinsic viscosity IV _A of polyester _A and the intrinsic viscosity IV _B of polyester B is in the range of 0.10 to 0.30 deciliter / gram , and the crystallization temperature of polyester A is raised and the temperature of polyester B is raised The difference in crystallization temperature is within 10 ° C., and at least one resin selected from the group consisting of polyolefin resin, polyamide resin, and polyacetal resin is blended in an amount of 0.1 ppb to 1000 ppm. A polyester composition for a hollow molded article, a sheet-like product, or a stretched film .
Polyester A: Intrinsic viscosity IV _A is 0.60 to 0.75 deciliter / gram, acetaldehyde content is 10 ppm or less, crystallization temperature at temperature rise measured by DSC is 150 to 172 ° C., and crystallization temperature at temperature fall is Polyester that is 160-190 ° C.
Polyester B: Intrinsic viscosity IV _B is 0.73 to 0.90 deciliter / gram, acetaldehyde content is 10 ppm or less, crystallization temperature at temperature increase measured by DSC is 150 to 172 ° C., and crystallization temperature at temperature decrease is Polyester that is 160-190 ° C. A polyester composition comprising at least one resin selected from the group consisting of the following polyester A, polyester B, and polyolefin resin, polyamide resin, and polyacetal resin containing 85 mol% or more of ethylene terephthalate units, The blending ratio of polyester B is 95/5 to 5/95 by weight, and the blending amount of at least one resin selected from the group consisting of polyolefin resin, polyamide resin, and polyacetal resin is 0.1 ppb to 1000 ppm. And intrinsic viscosity IV of polyester A _A And polyester B intrinsic viscosity IV _B The difference between the crystallization temperature when the polyester A is raised and the difference between the crystallization temperature when the polyester B is raised is within 10 ° C. A polyester composition.
Polyester A: Intrinsic viscosity IV _A Is a polyester having an acetaldehyde content of 10 ppm or less, a crystallization temperature at a temperature rise of 150 to 172 ° C. measured by DSC, and a crystallization temperature at a temperature drop of 160 to 190 ° C. .
Polyester B: Intrinsic viscosity IV _B Of 0.73 to 0.90 deciliter / gram, acetaldehyde content of 10 ppm or less, a crystallization temperature measured by DSC of 150 to 172 ° C., and a crystallization temperature of 160 to 190 ° C. . The bulk density of the polyester A and polyester B chips is 0.80 to 0.97 grams / cubic centimeter, and the difference between the bulk density of the polyester A chips and the bulk density of the polyester B chips is within 0.10 grams / cubic centimeter. the polyester composition of claim 1 or 2, characterized in that. The polyester composition according to any one of claims 1 to 3 , wherein the content of the cyclic trimer is 0.70% by weight or less. The polyester composition according to any one of claims 1 to 4 , wherein a fine content of the polyester composition is 0.1 to 5000 ppm. The polyester composition according to claim 5 , wherein a melting point of the fine measured by DSC is 265 ° C. or less. The polyester composition according to any one of claims 1 to 6, wherein an increase amount of the cyclic trimer when melted at a temperature of 290 ° C for 60 minutes is 0.40% by weight or less. Polyester molded body characterized by being obtained by molding the polyester composition according to any one of claims 1-7. 9. The polyester molding according to claim 8, wherein the polyester molding is any one of a hollow molding, a sheet-like material, and a stretched film obtained by stretching the sheet-like material in at least one direction. body.

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