JP2005290392A - Method for producing polyester - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a polyester which can obtain forms that has good long-term continuous moldability, transparency, and heat-resistant dimensional stability, and which can obtain forms that is slight in crystallization rate variation, especially heat-resistant blow-molded forms. <P>SOLUTION: The method for producing a polyester comprises carrying out a contact treatment of chips of a polyester obtained mainly from an aromatic dicarboxylic acid component and a glycol component with at least one member selected from the group consisting of a polyolefin resin member, a polyamide resin member, a polyacetal resin member, and a polybutylene terephthalate resin member under fluid conditions, wherein the speed of the polyester chips on contact with the members is ≤50 km/h. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for producing a polyester that is suitably used as a raw material for hollow molded articles such as beverage bottles, films, sheets and the like, and in particular, for transparency and heat-resistant dimensional stability. The present invention relates to a method for producing a polyester that provides a hollow molded article having excellent crystallization speed fluctuation and a sheet-like product having excellent transparency, slipperiness and dimensional stability after molding. The present invention also relates to a method for producing a polyester that has good releasability from a heat treatment mold when molding a hollow molded body and is excellent in long-term continuous formability.

  Polyesters whose main repeating unit is ethylene terephthalate (hereinafter sometimes abbreviated as “PET”) are carbonated beverages, juicy drinks, juices, etc. due to their excellent properties such as transparency, mechanical strength, heat resistance, and gas barrier properties. It is used as a material for containers such as water and mineral water, and its spread is remarkable. In these applications, beverages that have been sterilized at high temperatures are hot-filled in polyester bottles, or sterilized at high temperatures after filling beverages. However, ordinary polyester bottles shrink during such hot-filling treatments. Deformation occurs and becomes a problem. As methods for improving the heat resistance of polyester bottles, methods have been proposed in which the bottle cap is heat treated to increase the degree of crystallinity and the stretched bottle is heat-set. In particular, 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 the case of beverages that require hot filling, such as fruit juice beverages, oolong tea, and mineral water, a method of crystallizing by heat treatment of the preform or the formed bottle cap portion (See Patent Documents 1 and 2). 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.

  Further, in order to improve the heat resistance of the bottle body, for example, as shown in Japanese Patent Publication No. 59-6216, a method of performing heat treatment with the temperature of the stretch blow mold set at a high temperature is employed (see Patent Document 3). . 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 bottles, and shortening of the heating time and mold contamination for crystallization of the plug part have become more serious from the viewpoint of productivity. .

  In addition, if PET is extruded into a sheet and vacuum molded, the resulting product is filled with food and a lid made of the same material is left and left to shrink, resulting in poor lid opening. In addition, if the molded body is left for a long period of time, shrinkage occurs and the lid cannot be formed.

  Various proposals have been made to solve such problems. For example, a method of adding an inorganic nucleating agent such as kaolin or talc to polyethylene terephthalate (see Patent Documents 4 and 5), a method of adding an organic nucleating agent such as montanic acid wax salt (see Patent Document 6.7) However, 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 Patent Document 8), but this method requires 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, which is not a preferable method in terms of economy and quality. Moreover, although the method (refer patent documents 9 and 10) which inserts a heat-resistant resin piece in a cap part is proposed, the productivity of a bottle is bad and there exists a problem also in recyclability.

  Also, a PET modification method by contacting a PET chip with a polyethylene member under flow conditions (see Patent Document 11), or PET by contacting with a member made of a polypropylene resin or a polyamide resin under similar conditions However, it has been found that it is very difficult to obtain a stable crystallization speed and transparency even by such a method.

JP 55-79237 A JP 58-110221 A Japanese Examined Patent Publication No.59-6216 JP-A-56-2342 Japanese Patent Laid-Open No. 56-21832 JP 57-125246 A JP-A-57-207639 Japanese Patent Laid-Open No. 5-105807 JP 61-259946 A JP-A-2-269638 JP-A-9-71639 Japanese Patent Laid-Open No. 11-209492

  The present invention solves the problems of the above conventional methods, can efficiently produce a molded body having excellent transparency and heat-resistant dimensional stability, and less crystallization rate fluctuation, particularly a heat-resistant hollow molded body, It is another object of the present invention to provide a method for producing a polyester excellent in long-term continuous formability with less staining of the mold.

  In order to achieve the above object, the polyester production method of the present invention comprises a polyester chip obtained mainly from an aromatic dicarboxylic acid component and a glycol component, a polyolefin resin member, a polyamide resin member, and a polyacetal resin member. In the method for producing a polyester that is contact-treated under flow conditions with at least one member selected from the group consisting of members made of polybutylene terephthalate resin, the speed of the polyester chip when contacting the member is 50 km / hour or less It is characterized by being.

In this case, it is preferable that the ratio A between the surface area (cm ² ) of the member and the contact processing amount (ton / hour) of the polyester chip per unit time satisfies the following formula.
A = [surface area of the member (cm ² )] / [contact processing amount of the polyester chip per unit time (ton / hour)]
= 6 to 5000
Here, the surface area of the member is the surface area of the member that may come into contact with the polyester chip under flow conditions. For example, when the member is installed in the piping of the chip transfer path, if a part of the surface of the member cannot be brought into contact with the chip depending on the installation method, the surface area is not included in the calculation of A.

  In this case, the content of either the fine content of the polyester before the contact treatment and / or the contact treatment, the film-like content, or the total content of the fine content and the film-like content is It is preferably 5000 ppm or less.

  Here, fine means a fine polyester powder that has passed through a sieve having a mesh size of 1.7 mm according to JIS-Z8801, and film-like material means a metal mesh with a nominal size of 5.6 mm according to JIS-Z8801. A film having a thickness of about 0.5 mm or less after two or more chips of the polyester remaining on the sieving sieve are fused or the chips that are cut larger than the normal shape are removed. This content is measured by the following measurement method.

In this case, the polyester chip has a sodium content, a magnesium content, a silicon content, and a calcium content in the cooling water in the chip forming step after the melt polycondensation, respectively, as N, M, S, and C. In this case, it is preferable to use a cooling water that satisfies at least one of the following (1) to (4).
N ≦ 1.0 (ppm) (1)
M ≦ 0.5 (ppm) (2)
S ≦ 2.0 (ppm) (3)
C ≦ 1.0 (ppm) (4)

In this case, it is preferable that the polyester before the contact treatment is subjected to solid phase polymerization.
In this case, it is preferable that the polyester before the contact treatment is a polyester having ethylene terephthalate as a main repeating unit.
In this case, the polyester before the contact treatment has a cyclic trimer increase amount of 0.50% by weight or less when the polyester is melted at a temperature of 290 ° C for 60 minutes. It is preferable that it is polyester of this.
In this case, the polyolefin resin is preferably at least one resin selected from the group consisting of a polyethylene resin and a polypropylene resin.
In this case, the polyamide resin is preferably a partially aromatic polyamide resin.

  By the above-described method for producing a polyester of the present invention, an aromatic dicarboxylic acid component and a glycol component, which are capable of efficiently producing a molded article having excellent transparency and heat-resistant dimensional stability and little crystallization rate fluctuation, Polyester obtained from can be obtained.

Hereinafter, embodiments of the method for producing a polyester of the present invention will be specifically described.
The polyester according to the present invention is a polyester mainly obtained from an aromatic dicarboxylic acid component and a glycol component, more preferably a polyester containing an aromatic dicarboxylic acid unit of 85 mol% or more of the acid component, particularly preferably. Is a polyester in which aromatic dicarboxylic acid units contain 95 mol% or more of the acid component.

  The aromatic dicarboxylic acid component constituting the polyester according to the present invention includes aromatic dicarboxylic acids such as terephthalic acid, 2,6-naphthalenedicarboxylic acid, diphenyl-4,4′-dicarboxylic acid, and diphenoxyethanedicarboxylic acid. And functional derivatives thereof.

  Examples of the glycol component constituting the polyester according to the present invention include alicyclic glycols such as ethylene glycol, 1,3-trimethylene glycol, tetramethylene glycol, and cyclohexanedimethanol.

  Examples of the acid component used by copolymerization in the polyester include fragrances such as terephthalic acid, 2,6-naphthalenedicarboxylic acid, isophthalic acid, diphenyl-4,4′-dicarboxylic acid, and diphenoxyethanedicarboxylic acid. Oxyacids such as aliphatic dicarboxylic acids, p-oxybenzoic acid, oxycaproic acid and functional derivatives thereof, aliphatic dicarboxylic acids such as adipic acid, sebacic acid, succinic acid, glutaric acid, dimer acid, and functional derivatives thereof, Examples thereof include alicyclic dicarboxylic acids such as hexahydroterephthalic acid, hexahydroisophthalic acid, and cyclohexanedicarboxylic acid, and functional derivatives thereof.

  Examples of the glycol component used by copolymerization in the polyester include ethylene glycol, 1,3-trimethylene glycol, tetramethylene glycol, diethylene glycol, neopentyl glycol and other aliphatic glycols, cyclohexane dimethanol and the like. Alicyclic glycols, aromatic glycols such as bisphenol A and alkylene oxide adducts of bisphenol A, and polyalkylene glycols such as polyethylene glycol and polybutylene glycol.

  Furthermore, polyfunctional compounds such as trimellitic acid, trimesic acid, pyromellitic acid, tricarballylic acid, glycerin, pentaerythritol, trimethylolpropane and the like may be copolymerized within the range in which the polyester is substantially linear, Monofunctional compounds such as benzoic acid and naphthoic acid may be copolymerized.

  A preferred example of the thermoplastic polyester used in the present invention is a thermoplastic polyester whose main repeating unit is composed of ethylene terephthalate, and more preferably contains 85 mol% or more of ethylene terephthalate units, It is a linear copolymer thermoplastic polyester containing isophthalic acid, 2,6-naphthalenedicarboxylic acid, 1,4-cyclohexanedimethanol and the like as a component, and particularly preferably a line containing 95 mol% or more of ethylene terephthalate units. It is a thermoplastic polyester.

  Examples of these linear thermoplastic polyesters include polyethylene terephthalate (hereinafter abbreviated as PET), poly (ethylene terephthalate-ethylene isophthalate) copolymer, poly (ethylene terephthalate-1,4-cyclohexanedimethylene terephthalate) copolymer. Examples thereof include a polymer, a poly (ethylene terephthalate-ethylene-2,6-naphthalate) copolymer, and a poly (ethylene terephthalate-dioxyethylene terephthalate) copolymer.

  Another preferred example of the thermoplastic polyester used in the present invention is a thermoplastic polyester whose main repeating unit is composed of ethylene-2,6-naphthalate, more preferably ethylene-2,6-naphthalate. It is a linear thermoplastic polyester containing 85 mol% or more of a vinyl unit, and a linear thermoplastic polyester containing 95 mol% or more of an ethylene-2,6-naphthalate unit is particularly preferable.

  Examples of these linear thermoplastic polyesters include polyethylene-2,6-naphthalate, poly (ethylene-2,6-naphthalate-ethylene terephthalate) copolymer, poly (ethylene-2,6-naphthalate-ethylene isophthalate). Examples thereof include a copolymer and a poly (ethylene-2,6-naphthalate-dioxyethylene-2,6-naphthalate) copolymer.

  Other preferable examples of the polyester according to the present invention include linear polyesters containing 85 mol% or more of propylene terephthalate units, linear polyesters containing 85 mol% or more of 1,4-cyclohexanedimethylene terephthalate units, or butylene terephthalate units. Is a linear polyester containing 85 mol% or more.

  Said polyester can be manufactured by a conventionally well-known manufacturing method. That is, in the case of PET, terephthalic acid is directly reacted with ethylene glycol and, if necessary, other copolymerization components to distill off water and esterify, followed by polyesterification under reduced pressure. Or by transesterification in which dimethyl terephthalate is reacted with ethylene glycol and other copolymerization components as required to distill off methyl alcohol and transesterify, followed by polycondensation under reduced pressure. Is done.

  Furthermore, if necessary, the intrinsic viscosity is increased, and a low acetaldehyde content or a low cyclic trimer content is required, such as a heat-resistant container for low flavor beverages or an inner film of a beverage metal can. In this case, the melt polycondensed polyester thus obtained is solid-phase polymerized.

  The melt polycondensation reaction may be performed in a batch reactor or may be performed in a continuous reactor. In any of these methods, the melt polycondensation reaction may be performed in one stage or may be performed in multiple stages. The solid phase polymerization reaction can be carried out by a batch type apparatus or a continuous type apparatus, similarly to the melt polycondensation reaction. Melt polycondensation and solid phase polymerization may be carried out continuously or separately.

  Examples of the starting materials dimethyl terephthalate, terephthalic acid or ethylene glycol include virgin dimethyl terephthalate derived from paraxylene, ethylene glycol derived from terephthalic acid or ethylene, and methanol from used PET bottles. Recovered raw materials such as dimethyl terephthalate, terephthalic acid, bishydroxyethyl terephthalate or ethylene glycol recovered by chemical recycling methods such as decomposition and ethylene glycol decomposition 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.

Hereinafter, an example of a preferable production method in a continuous system will be described by taking polyethylene terephthalate as an example.
First, a case where a low polymer is produced by an esterification reaction will be described. A slurry containing 1.02 to 1.7 mol, preferably 1.03 to 1.4 mol, of ethylene glycol with respect to 1 mol of terephthalic acid or its ester derivative is prepared, and this is esterified. Supply continuously to the process.

In the esterification reaction, water or alcohol produced by the reaction is systematized in a rectifying column under conditions where ethylene glycol is refluxed using a multistage apparatus in which at least two esterification reactors are connected in series. Carry out while removing outside. 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 (total 5 mol% or less) with respect to the diol component.

  Next, when a low polymer is produced by a transesterification reaction, 1.1 to 1.6 mol, preferably 1.2 to 1.5 mol of ethylene glycol is contained per 1 mol of dimethyl terephthalate. The prepared solution is prepared and continuously fed to the transesterification step.

  In the transesterification reaction, methanol produced by the reaction is removed from the system by a rectification column under the condition that ethylene glycol is distilled back using an apparatus in which one or two transesterification reactors are connected in series. Perform while removing. 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.

  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.

  The polycondensation reaction uses a polycondensation catalyst. As the polycondensation catalyst, a compound of Ge, Sb, Ti, or Al is used, but a mixed catalyst of Ge compound and Ti compound, Ge compound and Al compound, Sb compound and Ti compound, Sb compound and Ge compound can also be used. Convenient. 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, germanium tetroxide, germanium hydroxide, germanium oxalate, germanium chloride, germanium tetraethoxide, germanium tetra-n-butoxide, germanium phosphite, and the like. When a Ge compound is used, the amount used is 10 to 150 ppm, preferably 13 to 100 ppm, more preferably 15 to 70 ppm as the residual amount of Ge in the polyester resin.

  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, acetic acid. Titanium oxalate compounds such as titanium, titanyl oxalate, titanyl ammonium oxalate, sodium titanyl oxalate, potassium titanyl oxalate, calcium titanyl oxalate, titanyl strontium oxalate, trimellitic acid titanium, titanium sulfate, titanium chloride, titanium halide hydrolyzate, sulphate Titanium fluoride, titanium fluoride, potassium hexafluorotitanate, ammonium hexafluorotitanate, cobalt hexafluorotitanate, manganese hexafluorotitanate, titanium acetylacetonate, and the like. The Ti compound is added so that the residual amount of Ti in the produced polymer is in the range of 0.1 to 10 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 in the range of 50 to 250 ppm.

  Specific examples of the Al compound include aluminum formate, aluminum acetate, basic aluminum acetate, aluminum propionate, aluminum oxalate, aluminum acrylate, aluminum laurate, aluminum stearate, aluminum benzoate, aluminum trichloroacetate, Carboxylates such as aluminum lactate, aluminum citrate and aluminum salicylate, inorganics such as aluminum chloride, aluminum hydroxide, aluminum hydroxide chloride, polyaluminum chloride, aluminum nitrate, aluminum sulfate, aluminum carbonate, aluminum phosphate and aluminum phosphonate Acid salt, aluminum methoxide, aluminum ethoxide, aluminum n-propoxide, aluminum iso-propoxide, aluminum Aluminum alkoxides such as n-butoxide, aluminum t-butoxide, aluminum acetylacetonate, aluminum acetylacetate, aluminum ethylacetoacetate, aluminum ethylacetoacetate diiso-propoxide, etc., organic compounds such as trimethylaluminum, triethylaluminum, etc. Examples thereof include aluminum compounds and partial hydrolysates thereof, and aluminum oxide. Of these, carboxylates, inorganic acid salts and chelate compounds are preferred, and among these, basic aluminum acetate, aluminum chloride, aluminum hydroxide, aluminum hydroxide chloride, polyaluminum chloride and aluminum acetylacetonate are particularly preferred. The Al compound is added so that the Al remaining amount in the produced polymer is in the range of 5 to 200 ppm.

  These catalyst compounds can be used, for example, as an ethylene glycol solution at any stage from the end of the transesterification process or from the end of the transesterification reaction to the start of the polycondensation reaction, It can be added at any stage.

  Moreover, in the manufacturing method of polyester of this invention, you may use together an alkali metal compound or an alkaline-earth metal compound. 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. These alkali metal compounds and alkaline earth metal compounds can be added at any stage of the polyester production reaction step.

  Moreover, various P compounds can be used as a stabilizer. P compounds used in the present invention include phosphoric acid compounds, phosphorous acid compounds, phosphonic acid compounds, phosphinic acid compounds, phosphine oxide compounds, phosphonous acid compounds, phosphinic acid compounds, phosphines. System compounds. 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 dimethylester, phenylphosphonic acid diethylester, phenylphosphonic acid Diphenyl ester, dimethyl benzylphosphonate, diethyl benzylphosphonate, diphenylphosphinic acid, methyl diphenylphosphinate, diphenylphosphinic acid phenyl , Phenylphosphinic acid, methyl phenylphosphinate, phenylphenylphosphinate, diphenylphosphine oxide, methyldiphenylphosphine oxide, triphenylphosphine oxide, etc., which may be used alone or in combination of two or more. Also good. The P compound can be added at any stage of the polyester production reaction step so that the residual amount of P in the produced polymer is in the range of 1 to 1000 ppm.

  Next, in order to reduce the acetaldehyde content as necessary, the polyester is subjected to solid phase polymerization by a conventionally known method. First, the polyester subjected to solid phase polymerization is pre-crystallized by heating at a temperature of 100 to 210 ° C. for 1 to 5 hours in an inert gas, under reduced pressure, or in an atmosphere of water vapor or water vapor-containing inert gas. The Subsequently, solid state polymerization is performed at a temperature of 190 to 230 ° C. for 1 to 30 hours in an inert gas atmosphere or under reduced pressure.

The intrinsic viscosity of the polyester obtained by the production method of the present invention, in particular, the polyester whose main repeating unit is composed of ethylene terephthalate is 0.55 to 2.00 deciliter / gram, preferably 0.60 to 1.70 deciliter / gram. More preferably, it is in the range of 0.70 to 1.50 deciliter / gram. When the intrinsic viscosity is less than 0.55 deciliter / gram, the mechanical properties of the obtained molded article are poor. On the other hand, if it exceeds 2.00 deciliters / gram, the resin temperature becomes high when melted by a molding machine or the like, resulting in severe thermal decomposition, increasing the amount of free low molecular weight compounds that affect the fragrance retention, Problems such as yellowing occur.

  The intrinsic viscosity of the polyester obtained by the production method of the present invention, in particular, the polyester whose main repeating unit is composed of ethylene-2,6-naphthalate is 0.40 to 1.50 deciliter / gram, preferably 0.42 to The range is 1.00 deciliter / gram, more preferably 0.45 to 0.90 deciliter / gram. When the intrinsic viscosity is less than 0.40 deciliter / gram, the mechanical properties of the obtained molded article and the like are poor. On the other hand, if it exceeds 1.50 deciliters / gram, the resin temperature becomes high when melted by a molding machine or the like, resulting in severe thermal decomposition, increasing the amount of free low molecular weight compounds that affect the fragrance retention, Problems such as yellowing occur.

  The shape of the polyester chip may be any of a cylinder shape, a square shape, a spherical shape or a flat plate shape, and the average particle size is usually 1.5 to 5 mm, preferably 1.6 to 4.5 mm. Preferably it is the range of 1.8-4.0 mm. For example, in the case of a cylinder type, it is practical that the length is about 1.5 to 4 mm and the diameter is about 1.5 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 10 to 40 mg / piece.

Further, when the sodium content, the magnesium content, the silicon content, and the calcium content in the cooling water of the chip forming process are N, M, S, and C, respectively, the following (1) to (4) It is preferable to chip the melt polycondensed polyester so as to satisfy at least one, preferably all of the above.
N ≦ 1.0 (ppm) (1)
M ≦ 0.5 (ppm) (2)
S ≦ 2.0 (ppm) (3)
C ≦ 1.0 (ppm) (4)

Here, the sodium content (N) in the cooling water is preferably N ≦ 0.5 ppm, more preferably N ≦ 0.1 ppm.
The magnesium content (M) in the cooling water is preferably M ≦ 0.3 ppm, more preferably M ≦ 0.1 ppm.
Further, the content (S) of silicon in the cooling water is preferably S ≦ 0.5 ppm, and more preferably S ≦ 0.3 ppm.
Furthermore, the calcium content (C) in the cooling water is preferably C ≦ 0.5 ppm, more preferably C ≦ 0.1 ppm.

  Further, the lower limit values of the sodium content (N), the magnesium content (M), the silicon content (S), and the calcium content (C) in the cooling water are N ≧ 0.001 ppm, M ≧ 0.001 ppm, S ≧ 0.02 ppm and C ≧ 0.001 ppm. In order to make it below such a lower limit value, enormous capital investment is required, and the operating cost is very high, so that economical production is difficult.

  When cooling water that does not satisfy the above conditions is used, these metal-containing compounds adhere to the surface of the polyester chip, and the crystallization rate of the final polyester obtained is very fast, and the variation becomes unfavorable. .

  Further, when the melt polycondensation polyester formed into a chip while cooling with cooling water that does not satisfy the above conditions is solid-phase polymerized, the metal adhered to the chip surface in the chip-forming step and brought into the solid-phase polymerization reactor The contained substance adheres to the container wall of the solid-phase polymerization apparatus together with a part of the surface layer of the polyester chip, and this becomes a scale with a high metal content by long-time heating at a high temperature of about 170 ° C. or higher. Adhere. And this peels off occasionally and mixes in a polyester chip, and it becomes a foreign substance in molded objects, such as a bottle, and the problem that a commercial value falls arises.

  Further, when manufacturing a sheet, the scale is clogged in the molten polymer filtration filter at the time of film formation, so that the filter filtration pressure increases sharply, resulting in poor operability and productivity. Also occurs.

  Although the method of restraining the sodium content of the cooling water of a chip | tip, magnesium content, silicon content, and calcium content to the said range is illustrated below, this invention is not limited to this.

In order to reduce sodium, magnesium, calcium, and silicon in the cooling water, an apparatus for removing sodium, magnesium, calcium, and silicon is installed in at least one place until the industrial water is sent to the chip forming process. Also, a filter is installed to remove clay minerals such as silicon dioxide and aluminosilicate particles. Examples of the device for removing sodium, magnesium, calcium, and silicon include an ion exchange device, an ultrafiltration device, and a reverse osmosis membrane device.
In addition, it is desirable to use water in which particles having a particle diameter of 1 to 25 μm existing in the introduced water introduced from outside the system are reduced to 50000/10 ml or less. The number of particles having a particle diameter of 1 to 25 μm in the introduced water is preferably 10,000 / 10 ml or less, more preferably 1000/10 ml or less, and particularly preferably 100/10 ml or less.

  Further, the content of dialkylene glycol copolymerized in the thermoplastic polyester according to the present invention is preferably 0.5 to 5.0 mol%, more preferably 1. mol% of the glycol component constituting the thermoplastic polyester. It is 0-4.5 mol%, More preferably, it is 1.5-4.0 mol%. When the amount of dialkylene glycol exceeds 5.0 mol%, the thermal stability is deteriorated, the decrease in molecular weight becomes large at the time of molding, and the increase in the content of aldehydes is unfavorable. In order to produce a thermoplastic polyester having a dialkylene glycol content of less than 0.5 mol%, it is necessary to select uneconomic production conditions as transesterification conditions, esterification conditions or polymerization conditions, Cost does not match. Here, the dialkylene glycol copolymerized in the thermoplastic polyester, for example, in the case of a polyester whose main structural unit is ethylene terephthalate, is a diethylene glycol produced as a by-product during production from ethylene glycol, which is glycol. Among them, diethylene glycol (hereinafter abbreviated as DEG) copolymerized with the thermoplastic polyester, and in the case of a polyester having 1,3-propylene terephthalate as a main structural unit, Di (1,3-propylene glycol) (or bis (3-hydroxypropyl) ether) by-produced from 1,3-propylene glycol, which is a glycol, as a by-product during the production, is a copolymer copolymerized with the thermoplastic polyester. (1,3-propylene glycol (hereinafter referred to as DPG)). .

  The content of aldehydes such as acetaldehyde in the thermoplastic polyester according to the present invention is 50 ppm or less, preferably 30 ppm or less, more preferably 10 ppm or less. In particular, when the polyester obtained by the production method of the present invention is used as a material for a container for low flavor beverages such as mineral water, the content of aldehydes in the thermoplastic polyester is 8 ppm or less, preferably 5 ppm. Hereinafter, it is desirable that the content is 4 ppm or less. When the aldehyde content exceeds 50 ppm, the effect of flavor retention of contents such as a molded article molded from this thermoplastic polyester is deteriorated. Further, these lower limits are preferably 0.1 ppb from the viewpoint of production. Here, the aldehydes are acetaldehyde when the thermoplastic polyester is a polyester having ethylene terephthalate as the main constituent unit, and in the case of polyester having 1,3-propylene terephthalate as the main constituent unit. Allyl aldehyde.

  Further, the content of the cyclic ester oligomer of the thermoplastic polyester according to the present invention is 70% or less, preferably 60% or less, more preferably 70% or less of the content of the cyclic ester oligomer contained in the melt polycondensate of the thermoplastic polyester. It is preferably 50% or less, particularly preferably 35% or less.

  Here, the thermoplastic polyester generally contains cyclic ester oligomers having various degrees of polymerization, but the cyclic ester oligomer referred to in the present invention is the most contained among the cyclic ester oligomers contained in the thermoplastic polyester. It means a cyclic ester oligomer having a high amount. For example, in the case of a polyester having ethylene terephthalate as a main repeating unit, it is a cyclic trimer.

In the case where the thermoplastic polyester is PET which is a representative polyester having ethylene terephthalate as a main constituent unit, the content of the cyclic trimer of the melt polycondensed polyester is about 1.0% by weight. The content of the cyclic trimer of the thermoplastic polyester according to the present invention is 0.70% by weight or less, preferably 0.60% by weight or less, more preferably 0.50% by weight or less, particularly preferably 0.35% by weight. % Or less is preferable.
Such a polyester having a reduced content of cyclic ester oligomer can be obtained by a method such as solid-phase polymerization of a melt polycondensed polyester or a heat treatment under an inert gas at a temperature below the melting point.

  Furthermore, in the present invention, the polyester before contact treatment with the thermoplastic resin member has an increase in cyclic ester oligomer when melted at a temperature of 290 ° C. for 60 minutes, more preferably 0.50% by weight or less. Is 0.30% by weight or less, more preferably 0.10% by weight or less of polyester.

  Polyester having an increase in cyclic ester oligomer of 0.50% by weight or less when melted for 60 minutes at a temperature of 290 ° C. deactivates the polyester polycondensation catalyst obtained after melt polycondensation or after solid phase polymerization. Can be manufactured. Examples of the method for deactivating the polyester polycondensation catalyst include a method in which the polyester chip is contacted with water, water vapor or water vapor-containing gas after melt polycondensation or after solid phase polymerization. Another method for deactivating the polycondensation catalyst is to inactivate the polymerization catalyst by adding and mixing the phosphorus compound to the melt of the polyester after melt polycondensation or solid phase polymerization.

In the case of solid-phase polymerization PET, the density of the obtained polyester is 1.37 g / cm ³ or more, preferably 1.38 g / cm ³ or more, more preferably 1.39 g / cm ³ or more.

  In order to increase the crystallization rate of the molded product obtained from the polyester and to suppress the fluctuation thereof, the polyester obtained by melt polycondensation as described above, or obtained by melt polycondensation and subsequent solid phase polymerization. The polyester is in the form of a chip at least one resin selected from the group consisting of a polyolefin resin member, a polyamide resin member, a polyacetal resin member, and a polybutylene terephthalate resin member (hereinafter abbreviated as "thermoplastic resin"). It may be contacted with a manufactured member.

  The polyester production method of the present invention comprises a polyester chip obtained mainly from an aromatic dicarboxylic acid component and a glycol component, a polyolefin resin member, a polyamide resin member, a polyacetal resin member, a polybutylene terephthalate resin member. In the method for producing a polyester that is subjected to contact treatment under flow conditions with at least one member selected from the group consisting of: a speed of the polyester chip when contacting the member is 50 km / hour or less. .

  The speed of the polyester chip when contacting the member is preferably 40 km / hour or less, more preferably 30 km / hour or less. When the speed of the polyester chip in contact with the member exceeds 50 km / hour, the blending amount of the thermoplastic resin in the polyester may be excessive, and the variation of the blending amount may become very large. For this reason, the crystallization speed of the obtained molded body may be increased or the fluctuation thereof may be very large. And the crystallization of the plug part of the hollow molded body becomes excessive, and therefore the shrinkage amount of the plug part does not fall within the specified value range, so that the capping part of the plug part becomes defective and the content leaks. The preform for use in whitening may be whitened, so that normal stretching may not be possible. In addition, since the speed of the polyester chip when contacting the member is very fast, the impact force to the member is increased, the member is scraped or peeled off, and sometimes the average particle size is about 0.5 to It will be mixed in the polyester chip | tip which was contact-processed in the state independent of the polyester chip | tip in the form of the granule of the magnitude | size of several millimeters, or a lump. In such a case, the thermoplastic resin becomes a foreign substance in the obtained molded body, and as a result, the obtained molded body has a great number of defects such as thickness unevenness, voids, and whitening. The lower limit of the speed of the polyester chip in contact with the member is not particularly limited, but is about 1 km / hour or more due to equipment problems.

  Here, the speed of the polyester chip when contacting the thermoplastic resin member means that, for example, when the member is installed in a space such as a transport pipe and the polyester chip collides with the member, the polyester chip collides with the member. It means the speed of the chip.

Further, the polyester production method of the present invention comprises a polyester chip obtained mainly from an aromatic dicarboxylic acid component and a glycol component, a polyolefin resin member, a polyamide resin member, a polyacetal resin member, and a polybutylene terephthalate resin. In the method for producing polyester, which is subjected to contact treatment under flow conditions with at least one member selected from the group consisting of manufactured members, the surface area (cm ² ) of the member and the contact treatment amount of the polyester chip per unit time (ton / ) Ratio A satisfies the following formula.

A = [surface area of the member (cm ² )] / [contact processing amount of the polyester chip per unit time (ton / hour)]
= 6 to 5000

The ratio A between the surface area (cm ² ) of the member and the contact treatment amount (ton / hour) of the polyester chip per unit time is preferably 8 to 4000, more preferably 10 to 3000. When the ratio A between the surface area (cm ² ) of the member and the contact processing amount (ton / hour) of the polyester chip per unit time is less than 6, the blending amount of the thermoplastic resin into the polyester is reduced. For this reason, the crystallization speed of the obtained molded product is insufficient, and the fluctuation may be large. Then, the plug portion of the hollow molded body is insufficiently crystallized. For this reason, the shrinkage amount of the plug portion does not fall within the specified value range, and a capping failure phenomenon may occur. When the ratio A between the surface area (cm ² ) of the member and the contact processing amount (ton / hour) of the polyester chip per unit time exceeds 5000, the amount of the thermoplastic resin blended into the polyester is excessive, In addition, the variation of the blending amount may become very large. For this reason, the crystallization speed of the obtained molded body may be increased or the fluctuation thereof may be very large. And the crystallization of the plug part of the hollow molded body becomes excessive, and therefore the shrinkage amount of the plug part does not fall within the specified value range, so that the capping part of the plug part becomes defective and the content leaks. The preform for use in whitening may be whitened, so that normal stretching may not be possible.

  Examples of the polyolefin resin used in the present invention include a polyethylene resin, a polypropylene resin, and an α-olefin resin. These resins may be crystalline or amorphous.

  Examples of the polyethylene resin used in the present invention include ethylene homopolymer, ethylene, propylene, butene-1, 3-methylbutene-1, pentene-1, 4-methylpentene-1, hexene-1, and octene. -1, and other α-olefins having about 2 to 20 carbon atoms such as decene-1, vinyl acetate, vinyl chloride, acrylic acid, methacrylic acid, acrylic ester, methacrylic ester, styrene, unsaturated epoxy compounds, etc. Examples thereof include a copolymer with a vinyl compound. 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.

  Examples of the polypropylene resin used in the present invention include propylene homopolymer, propylene, ethylene, butene-1, 3-methylbutene-1, pentene-1, 4-methylpentene-1, hexene-1, With other α-olefins having about 2 to 20 carbon atoms such as octene-1 and decene-1, and vinyl compounds such as vinyl acetate, vinyl chloride, acrylic acid, methacrylic acid, acrylic ester, methacrylic ester and styrene Examples thereof include copolymers and copolymers with dienes such as hexadiene, octadiene, decadiene, and 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 used in the present invention is a homopolymer of α-olefin having about 2 to 8 carbon atoms such as 4-methylpentene-1, such α-olefin, ethylene, propylene, butene- Examples thereof include copolymers with other α-olefins having about 2 to 20 carbon atoms such as 1,3-methylbutene-1, pentene-1, hexene-1, octene-1, and decene-1. 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.

  In addition, examples of the polyamide resin used in the present invention include polymers of lactam such as butyrolactam, δ-valerolactam, ε-caprolactam, enantolactam, ω-laurolactam, 6-aminocaproic acid, 11-aminoundecanoic acid, Polymer of aminocarboxylic acid such as 12-aminododecanoic acid, hexamethylenediamine, nonamethylenediamine, decamethylenediamine, dodecamethylenediamine, undecamethylenediamine, 2,2,4- or 2,4,4-trimethylhexa Aliphatic diamines such as methylenediamine, alicyclic diamines such as 1,3- or 1,4-bis (aminomethyl) cyclohexane, bis (p-aminocyclohexylmethane), and fragrances such as m- or p-xylylenediamine Diamine units such as group diamines, glutaric acid, Polycondensates with dicarboxylic acid units such as dipic acid, suberic acid, sebacic acid and other aliphatic dicarboxylic acids, cyclohexanedicarboxylic acid and other alicyclic dicarboxylic acids, terephthalic acid and isophthalic acid and other aromatic dicarboxylic acids, and the like 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 6/66, nylon 6/610, nylon 6/12 aliphatic polyamide, nylon 6T, nylon 6I, nylon MXD6, nylon 6 / MXD6, nylon MXD6 / MXDI, nylon 6 / 6T, nylon 6I / 6T And partially aromatic polyamides. These resins may be crystalline or amorphous.

In addition, examples of the polyacetal resin used in the present invention include polyacetal homopolymers and copolymers. 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.

  The polybutylene terephthalate resin used in the present invention includes, for example, a polybutylene terephthalate homopolymer composed of terephthalic acid and 1,4-butanediol, naphthalenedicarboxylic acid, diethylene glycol, Examples include copolymers obtained by copolymerizing 1,4-cyclohexanedimethanol.

  Further, the lower limit of the blending ratio of the thermoplastic resin used in the present invention to the polyester is 0.1 ppb or more, preferably 0.3 ppb or more, more preferably 0.5 ppb or more, and further 1 ppb or more, and the upper limit is , 50,000 ppm or less, preferably 10,000 ppm or less, more preferably 100 ppm or less, still more preferably 1 ppm or less, and particularly preferably 45 ppb or less.

  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 may be insufficient. Therefore, if the cycle time is shortened, the plug part shrinks. Since the amount does not fall within the specified range, capping defects occur, and the heat-fixed mold for forming heat-resistant hollow molded bodies is heavily soiled. You may need to clean it. On the other hand, if it exceeds 50000 ppm, the crystallization speed will be high, and the crystallization of the plug part of the hollow molded body will be excessive, and the amount of shrinkage and shrinkage of the plug part will not fall within the specified value range. Leakage may occur, or the preform for the hollow molded body may be whitened, and normal stretching may not be possible. In the case of a sheet-like material, if it exceeds 50000 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. It may not be possible.

  As a method of bringing polyester into contact treatment with at least one resin member selected from the group consisting of a polyolefin resin member, a polyamide resin member, a polyacetal resin member, and a polybutylene terephthalate resin member, In the space where the member exists, it is preferable to make the polyester collide with the member. Specifically, for example, immediately after the melt polycondensation or solid phase polymerization of the polyester, or in the transportation stage of the polyester as a product, etc. Pneumatic transportation piping, gravity transportation piping, silo, magnet part of magnet catcher, etc., when filling or discharging from the transportation container, or when inserting a molding machine at the polyester molding stage, etc. A part of the thermoplastic resin, or the resin film, sheet, molding Or the like, or the thermoplastic resin is lined, or the thermoplastic resin member such as a rod-like body, a plate-like body, a tubular body or a net-like body is installed in the transfer path, etc. The method of transferring polyester is mentioned. The contact time of the polyester with the member is usually a short time of about 0.01 seconds to several minutes. By such a contact treatment, the polyolefin resin, polyamide resin, polyacetal resin or polybutylene is added to the polyester. A small amount of terephthalate resin can be blended.

  When the polyester is contacted with the thermoplastic resin member, it is desirable that the thermoplastic resin is present on the surface of the polyester chip, but the impact when the polyester chip collides with the member. The thermoplastic resin member does not adhere to the polyester chip, that is, the polyester chip, depending on the magnitude of the force, the pressing force when contacting, or the properties of the thermoplastic resin member such as impact resistance and peel resistance. Some of them are in a state where they are mixed with the above-mentioned polyester chips subjected to the contact treatment. A molded body obtained from such a mixed polyester may have an excessively high crystallization rate or a very large fluctuation in the rate.

  In the case of a preform for a hollow molded body, the whitening and transparency spots thereof are severe, normal stretching is impossible, thick spots are large, and only a hollow molded body with poor transparency may be obtained. . In addition, although usually present as fine fine particles, sometimes the above-mentioned contact-treated polyester is in the form of granules or lumps having an average particle size of about 0.5 to several mm and independent of the polyester chip. Sometimes mixed. In such a case, the thermoplastic resin becomes a foreign substance in the obtained molded body, and as a result, the obtained molded body may have a lot of defects such as thickness spots, voids, and whitening. is there. Therefore, it is desirable to remove the thermoplastic resin fine granules, granules and lumps which are present independently of the polyester chip before molding.

  Examples of the method for separating and removing the fine particles, granules and aggregates of the thermoplastic resin from the polyester which has been contact-treated with the thermoplastic resin member include the following methods. That is, after the melt polycondensed polyester or solid-phase polymerized polyester is contacted with a member made of a thermoplastic resin, it is treated by a vibration sieving step and an airflow classification step by air flow, or by a water washing step by ion-exchanged water. These fine granular, granular and lump thermoplastic resins are removed by a method such as a method for performing a floating selection process or the like. Such a method of separating and removing fine particles, granules and lumps of the thermoplastic resin is also effective as a method for removing polyester fines and film-like materials described later.

  The melt-polycondensed polyester is chipped and then transported to a silo or the like in a transport pipe for storage, or transported to the next step such as a solid phase polymerization step or a water treatment step. Similarly, the solid-state polymerized polyester chip is also transported to the next process, silo or the like. When such chips are transported by a forced low-density transportation method using air, for example, a large impact force is applied to the surface of the polyester chip due to a collision with the pipe, and as a result, fine and film-like materials are formed. It occurs in large quantities. Part of the fines produced in this way and most of the film-like substances have a very high melting peak temperature exceeding 265 ° C. In addition, when the solid phase polymerization is performed using a rotary solid phase polymerization apparatus, or a feeding apparatus that applies impact force or shear force to a polyester chip is used as a transport method to the next process, Fine and film-like materials having melting peak temperatures exceeding 265 ° C. are generated. This is presumably because the chip generates heat due to a large force such as impact force applied to the chip surface, and at the same time, oriented crystallization of polyester occurs on the chip surface, resulting in a dense crystal structure.

  Polyester fines and film-like materials having a melting peak temperature exceeding 265 ° C. as described above can be obtained by subjecting them to solid phase polymerization treatment or water treatment together with polyester chips. The temperature is higher than before processing. Fine and film-like materials having a melting peak temperature of not more than 265 ° C. but considerably higher than the normal melting peak temperature also exceed the melting peak temperature of 265 ° C. by these treatments. It has a melting peak temperature. It is presumed that this is because the crystal structure changes to a finer crystal structure by these treatments.

  When a polyester containing fine or film-like material having a melting point peak higher than 265 ° C., which is higher than the normal melting point, is molded under normal molding conditions, the crystal does not completely melt during melt molding. It remains as a nucleus. As a result, the crystallization speed during heating increases, so the crystallization of the plug part of the hollow molded container becomes excessive, and the shrinkage amount of the plug part does not fall within the specified value range, and the cap part is capped. There may be a problem that the contents become defective and leakage of contents occurs. Also, the preform for hollow molding is whitened, so that normal stretching is impossible, thickness unevenness may occur, and the transparency of the obtained hollow molded body is deteriorated due to the high crystallization speed. And there may be a large variation in transparency.

  When a hollow molding preform or sheet having good transparency and stretchability is to be obtained from polyester containing fines having a melting peak temperature exceeding 265 ° C., a high temperature of 300 ° C. or higher is required. It must be melt molded at temperature. 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. In addition, when the polyester obtained by the production method of the present invention contains the thermoplastic resin as described above, the thermoplastic resin is often inferior in thermal stability to the polyester of the present invention. In molding at a high temperature of ℃ or higher, a large amount of by-products are generated due to thermal decomposition, so that the flavor of the contents such as the obtained molded product has a greater influence.

  Therefore, in the present invention, either the fine content, the film-like content, or the total content of the fine content and the film-like content of the polyester before and / or after the contact treatment with the member. By reducing the content to 5000 ppm or less, preferably 3000 ppm or less, more preferably 1000 ppm or less, still more preferably 500 ppm or less, and most preferably 100 ppm or less, the above problem can be further solved.

  The content of either the fine content of the polyester before the contact treatment with the member and / or after the contact treatment, the film-like content, or the total content of the fine content and the film-like content is 5000 ppm. In the case of exceeding, the crystallization speed of the molded product obtained from the obtained polyester becomes faster, so that the crystallization of the plug portion of the hollow molded container becomes excessive, and therefore the shrinkage amount of the plug portion is within the specified range. There is a possibility that the clogging of the plug portion is caused and the contents are leaked. Also, the preform for hollow molding is whitened, so that normal stretching is impossible, thickness unevenness may occur, and the transparency of the obtained hollow molded body is deteriorated due to the high crystallization speed. And there may be large variations in transparency. In particular, the fine content of the polyester composition for the hollow molded body is preferably 500 ppm or less.

  In the present invention, the highest peak temperature of the melting peak temperature of the fine contained in the polyester before and / or after the contact treatment with the member is 265 ° C. or less. Thus, the above problem can be further solved.

  Examples of a method for separating and removing fine and / or film-like substances from the polyester before and / or after the contact treatment with the member include the following methods. That is, in the case of the melt polycondensed polyester, there is a method in which the polyester is subjected to a vibration sieving step, an airflow classification step using an air flow, or the like immediately before or after the contact treatment with a member made of a thermoplastic resin. In the case of solid-phase polymerized polyester, a vibration sieving step and an airflow classification step using an air flow separately installed immediately before and immediately after the solid-phase polymerization step and immediately before or after the step of contact treatment with the thermoplastic resin member, And the like.

  As a method for preventing the fine peak and / or film-like material having a melting peak temperature on the highest temperature side of the melting peak exceeding 265 ° C. from being included, after the contact treatment with the thermoplastic resin, as described above. And a method of processing in a fine removal process.

  By using the polyester obtained by the above production method, it is possible to obtain a molded article that is excellent in transparency and has little fluctuation in the crystallization rate, but for the above reasons, before the contact treatment with the member made of the thermoplastic resin. It is necessary to pay attention to the content of fine and film-like materials contained in the polyester and the properties thereof.

Further, a specific example of a method for preventing the polyester before the contact treatment with the thermoplastic resin from containing fines having such a high melting point will be described below.
In the case of melt polycondensation polyester, chips are formed by either extruding the melt polyester into water after the melt polycondensation and cutting it in water, or by extruding into the air and then cutting it while cooling with cooling water. After draining the polyester chips formed into chips, chips, fines, and film-like objects with shapes other than the prescribed size are removed by the vibration sieving process and the airflow classification process by air flow or the water washing process, and the plug transport system and bucket It is sent to the storage tank by a conveyor system.

  Chip extraction from the tank is carried out by a screw feeder, and the next process is carried by a plug transportation system or a bucket conveyor transportation system, and airflow classification by an air flow immediately before or after the contact treatment process. Fine removal processing is performed according to the process. Further, in the case of solid-phase polymerized polyester, the melt polycondensed polyester subjected to the above-mentioned fine or film-like material removal treatment is again subjected to an air flow classification process using an air stream immediately before the solid-phase polymerization process. After removal, the solid phase polymerization process is performed. When transporting melt-polycondensed prepolymer chips to a solid-phase polymerization facility, or when transporting polyester chips after solid-phase polymerization to a sieving process, the contact treatment process or a storage tank, most of these transports Uses a plug transport system or bucket type conveyor transport system, and uses a screw feeder to extract chips from the crystallization equipment or solid-phase polymerization reactor. Use a device that can minimize the impact with the unit.

In the production process of polyester, it is filled into containers such as silos, molding machine hoppers, and transport containers through the melt polycondensation process, solid phase polymerization process, etc., through the sieving process and the airflow classification process. However, for transporting and drying polyester between these processes, air in the vicinity of the processing equipment is generally taken into the process by a blower or the like. Conventionally, such air is used as it is untreated or treated only by a cleaner equipped with a low-performance filter unit such as Type 3 defined in JIS B 9908 (1991). It was common to use.
However, there is a case in which only a molded article having poor transparency can be obtained from the polyester treated in such a process. In particular, when air of the above-mentioned quality is used as the gas that contacts the polyester before and after the contact treatment step with the member made of the thermoplastic resin, fluctuations in the crystallization speed and transparency of the obtained molded body Is likely to become a problem.

  Therefore, in the method for producing polyester by contact treatment with a member made of the thermoplastic resin of the present invention, after melt polycondensation, after solid-phase polymerization, after water treatment, or after contact treatment with a member made of the thermoplastic resin. Among the polyesters, at least one polyester has a particle size of 0.3 to 5 μm as a gas contacting in any one of the transport process to the next process, the sieving process, the storage process, and the container filling process. (Pieces / cubic foot) or less, preferably 500,000 (pieces / cubic foot) or less, more preferably 100,000 (pieces / cubic foot) or less, introduced from outside the system. desirable. The particles in the gas having a particle size exceeding 5 μm are not particularly limited, but are preferably 5 (pieces / cubic foot) or less, more preferably 1 (pieces / cubic foot) or less. Further, the particles having a particle size of less than 0.3 μm in the gas are not particularly defined, but in order to obtain a resin that gives a transparent molded product, the smaller one is preferable. The number of particles having a particle size of less than 0.3 μm is preferably 10000000 (pieces / cubic feet) or less, more preferably 5000000 (pieces / cubic feet), and even more preferably 2000000 (pieces / cubic feet). ).

  The polyester obtained by the production method of the present invention has a crystallization temperature (Tc1) at the time of raising the temperature of a test piece from a molded article having a thickness of 2 mm obtained by melt-molding the polyester in the range of 150 to 168 ° C, Preferably it is the range of 155-165 degreeC. When Tc1 exceeds 168 ° C., the heating crystallization rate is very slow, and the improvement effect of crystallization may not be expected. On the other hand, when Tc1 is less than 150 ° C., the transparency of the hollow molded body may be lowered, which may be a problem.

  For the polyester used in the present invention, other additives such as known ultraviolet absorbers, antioxidants, oxygen absorbers, oxygen scavengers, lubricants added from the outside, and internal precipitation during the reaction are carried out as necessary. Various additives such as lubricants, mold release agents, nucleating agents, stabilizers, antistatic agents, dyes and pigments may be blended.

  The polyester obtained by the above-described production method of the present invention is injection-molded and stretch-blow molded to be a stretched hollow molded body, and extruded to be molded into a sheet-like material.

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.
The main characteristic value measuring methods in this specification will be described below.

(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.

(2) Dialkylene glycol content copolymerized in polyester Decomposes with methanol, determines the amount of dialkylene glycol by gas chromatography, and in proportion (mol%) to the total glycol components expressed.
In the case of PET, the content is DEG.

(3) Content of cyclic ester oligomer 300 mg of a 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, made up to a constant volume with 10 ml of dimethylformamide, and cyclic ester oligomers were quantified by high performance liquid chromatography.
In the case of PET, it is a cyclic trimer (CT content).

(4) Acetaldehyde content of polyester (hereinafter referred to as “AA content”)
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 addition, the resin sample used the chip as it was, and in the case of the bottle, the resin cut out from the body portion was cut into about 3 mm square.

(5) Increasing amount of cyclic trimer at the time of melting polyester (△ CT amount)
3 g of the dried PET chip is put in a glass test tube and immersed in an oil bath at 290 ° C. for 60 minutes in a nitrogen atmosphere and melted. The increase amount of the cyclic trimer at the time of melting is obtained by the following equation.
Increase amount of cyclic trimer at the time of melting (wt%) =
Cyclic trimer content after melting (wt%)-cyclic trimer content before melting (wt%)

(6) Measurement of fine content and film-like content About 0.5 kg of resin, a sieve with a nominal size of 5.6 mm according to JIS-Z8801 (A) and a nominal size of 1.7 mm A sieve (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.
In the case where two or more chips fused to each other or a chip-shaped material cut to a size larger than the normal shape are captured separately from the film-shaped material on the sieve (A). The remaining film-like material from which the water was removed and the fine sieved under the sieve (B) were separately washed with ion-exchanged water and collected by filtration through a G1 glass filter manufactured by Iwaki Glass Co., Ltd. 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 a constant weight was reached, and the weight of the glass filter was subtracted from this weight to determine the fine weight and the weight of the film-like material. Fine content or film-like content is fine weight or film-like weight / total resin weight subjected to sieving. The total content is determined from these values.

(7) Melting point measurement of fine Measured using a differential scanning calorimeter (DSC), RDC-220 manufactured by Seiko Denshi Kogyo Co., Ltd. In (6),
Fines collected from 20 kg of polyester were dried under reduced pressure at 25 ° C. for 3 days, and then DSC measurement was performed at a heating rate of 20 ° C./min using 4 mg of sample for one measurement. Determine the melting peak temperature on the hottest side. 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.
(8) Average density of polyester chip, preform plug density and plug density deviation Measured at 30 ° C. with a density gradient tube of calcium nitrate / water mixed solution.
The plug portion density was determined as an average value of 10 samples crystallized by the method of (11), and the plug portion density deviation was determined from these 10 values.

(9) Haze (degree of haze%) and molded plate haze spots Samples were cut from the molded body (thickness 5 mm) below (12) and the hollow molded body (thickness about 0.45 mm) of (13), Measured with Nippon Denshoku Co., Ltd. haze meter, model NDH2000. Moreover, the haze of the molded board (thickness 5 mm) shape | molded 10 times continuously was measured, and the molded board haze spot was calculated | required by the following.
Molded plate haze spots (%) = maximum haze value (%)-minimum haze value (%)

(10) Crystallization temperature (Tc1) when the molded body is heated
Measured with a differential thermal analyzer (DSC), RDC-220, manufactured by Seiko Electronics Industry Co., Ltd. A 10 mg sample from the center of a 2 mm thick plate of the molded plate of (13) below is used. The temperature is raised at a rate of temperature rise of 20 degrees C / min, and the peak temperature of the crystallization peak observed in the middle is measured to obtain the crystallization temperature (Tc1) during temperature rise.

(11) Increase in density due to heating of preform plug part The preform plug part was heat-treated for 90 seconds with a homemade infrared heater, a sample was taken from the top surface, and the density was measured.

(12) Molding of Stepped Molding Plate In molding of the stepped molding plate according to this patent description, a polyester chip that has been dried under reduced pressure at 140 ° C. for about 16 hours using a vacuum dryer is an injection molding machine M- manufactured by Meiki Seisakusho. 1 to 2 mm having a gate part (G) as shown in FIGS. 1 and 2 by a 150 C-DM type injection molding machine (A part thickness = 2 mm, B part thickness = 3 mm, C part thickness = 4 mm, A stepped molding plate having a thickness of D part = 5 mm, E part = 10 mm, and F part = 11 mm) was injection molded.
A polyester chip previously dried under reduced pressure using a vacuum dryer DP61 manufactured by Yamato Scientific was used, and a dry inert gas (nitrogen gas) purge was performed in the molding material hopper in order to prevent moisture absorption of the chip 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 (A part in FIG. 1) is used for crystallization temperature (Tc1) measurement at elevated temperature, and a 5 mm-thick plate (D part in FIG. 1) is used for haze (degree of degree%) measurement.

(13) Molding of Hollow Molded Body The polyester was dried with a drier 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 each machine manufacturer. The preform plug part was crystallized by heating with a home-made plug part crystallizer. Next, this preform was biaxially stretched at a magnification of about 2.5 times in the longitudinal direction and about 3.8 times in the circumferential direction on an LB-01E molding machine manufactured by CORPOPLAST, and subsequently set at about 150 ° C. The container was heat-fixed in the mold for about 7 seconds to form a container (body thickness 0.45 mm) having a capacity of 2000 cc. The stretching temperature was controlled at 100 ° C.

(14) Evaluation of leakage of contents from hollow molded body After filling the hollow molded body molded in the above (13) with hot water of 90 ° C, capping with a capping machine, the container was tilted and allowed to leak, and the contents were leaked. Examined. The deformation state of the plug after capping was also examined.

(15) Sodium content, calcium content, magnesium content, and silicon content in the cooling water in the chip-forming process and the water introduced in the water treatment process The cooling water or introduced water that had been subjected to particle removal and ion exchange was collected, and Iwaki Glass After filtration with a 1G1 glass filter manufactured by KK, the filtrate was measured with an inductively coupled plasma emission spectrometer manufactured by Shimadzu Corporation.

(16) Measurement of the number of particles in the introduced water and recycled water during water treatment Particle measurement by the light blocking method of the introduced water after particle removal and ion exchange, or the recycled water treated by the filtration device (5) and the adsorption tower (8) It was measured using a PAC 150 manufactured by Seishin Enterprise Co., Ltd., and the number of particles was displayed in number / 10 ml.

(17) Measurement of the number of particles in the gas that comes into contact with the polyester chip Particles that are sent by a blower or the like for forcibly sending the gas and that have passed through the gas cleaning device branch off from the main gas stream before contacting the chip. Introduce into a measuring instrument and measure. The measurement is repeated five times, the average value is obtained, and the number per cubic foot of gas is calculated.
As a particle measuring device, a light scattering particle measuring device, KC-01B, manufactured by Rion Co., Ltd. was used.

(Example 1)
A slurry of high-purity terephthalic acid and ethyl glycol is continuously fed to the first esterification reactor containing the reactants in advance, and is stirred at about 250 ° C. and 0.5 kg / cm ² G. The reaction was carried out with an average residence time of 3 hours. 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. Further, crystalline germanium dioxide was dissolved in water by heating, ethylene glycol was added to the catalyst solution, and a heat-treated catalyst solution and an ethylene glycol solution of phosphoric acid were continuously supplied separately to the second esterification reactor. . The esterification reaction product is continuously fed to the first polycondensation reactor, and is stirred for about 1 hour at about 265 ° C. and 25 torr, and then stirred for about 2 hours at about 265 ° C. and 3 torr. The mixture was further subjected to polycondensation for about 1.5 hours at about 275 ° C. and 0.5 to 1 torr with stirring in the final polycondensation reactor. The obtained melt polycondensed PET had an intrinsic viscosity of 0.73 deciliter / gram and a cyclic trimer content of 1.0% by weight.

Obtained after chipping while cooling the melt polycondensation reaction product with cooling water (sodium content 0.02 ppm, magnesium content 0.02 ppm, calcium content 0.02 ppm, silicon content 0.05 ppm) The obtained PET chip was transported to a storage tank, and then fine and film-like substances were removed by a vibration sieving step and an airflow classification step, so that the total content thereof was about 20 ppm or less. Next, linear low density polyethylene (MI = approx. 0.9 g / 10 min, density = approx. 0.923 g) is connected to a part of the transport pipe made of SUS304 connected to the transport container filling process installed after the airflow classification process. The PET chip was transported at a speed of about 5 km / hour and a throughput of about 3 tons / hour in a transportation pipe connected with a cylindrical pipe having an inner diameter of 70 mm and a length of 700 mm made of / cm ³ , and contact treatment was performed. The ratio A of the surface area (cm ² ) of the cylindrical pipe to the throughput of the polyester per unit time (ton / hour) was about 513.

After the contact treatment, it was further treated in an airflow classification process. The fine content contained in the treated PET was about 25 ppm, and the peak temperature on the highest temperature side of the fine melting peak temperature was 265 ° C. or lower.
This PET was evaluated using a molded plate and a biaxially stretched bottle.
The haze of the stepped molded plate (5 mm thick) is 6.3%, the molded plate haze spot is 0.2%, Tc1 is 162 ° C., the density of the plug portion of the hollow molded body is 1.382 g / cm ³ , the plug The partial density deviation was 0.002 g / cm ³ , which was a satisfactory value, and the transparency of the bottle was also good at 1.5%.

(Example 2)
A slurry of high-purity terephthalic acid and ethyl glycol is continuously fed to the first esterification reactor containing the reactants in advance, and is stirred at about 250 ° C. and 0.5 kg / cm ² G. The reaction was carried out with an average residence time of 3 hours. 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 to a predetermined reactivity. Further, crystalline germanium dioxide was dissolved in water by heating, ethylene glycol was added to the catalyst solution, and a heat-treated catalyst solution and an ethylene glycol solution of phosphoric acid were continuously supplied separately to the second esterification reactor. . The esterification reaction product is continuously fed to the first polycondensation reactor, and is stirred for about 1 hour at about 265 ° C. and 25 torr, and then stirred for about 2 hours at about 265 ° C. and 3 torr. The mixture was further subjected to polycondensation at about 275 ° C. and 0.5 to 1 torr for 1 hour with stirring in the final polycondensation reactor. The intrinsic viscosity of the obtained melt polycondensed PET was 0.55 dl / g.

  The melt polycondensation reaction product is stored in chips after cooling with cooling water (sodium content is 0.02 ppm, magnesium content is 0.02 ppm, calcium content is 0.02 ppm, silicon content is 0.07 ppm). The total content of these was reduced to about 15 ppm or less by removing the fine and film-like substances by the vibration sieving step and the airflow classification step, and then the mixture was transferred to a continuous solid-phase polymerization apparatus. Crystallization was performed at about 155 ° C. in a nitrogen atmosphere, and after preheating to about 200 ° C. in a nitrogen atmosphere, the mixture was sent to a continuous solid-phase polymerization reactor and subjected to solid phase polymerization at about 207 ° C. in a nitrogen atmosphere.

Raw material chip supply port (1) at the upper part of the treatment tank, an overflow outlet (2) located at the upper limit level of the treated water in the treatment tank, and a discharge port for the mixture of polyester chips and treated water at the lower part of the treatment tank (3) ), The treated water discharged from the overflow outlet and the treated water passing through the draining device (4) for the polyester chip discharged from the outlet at the lower part of the treatment tank, the filter medium is a continuous filter -Fine filtration removal device (5) and pipe (6) sent again to the water treatment tank via the adsorption tower (8), ISP GAF filter-bag PE-1P2S (polyester felt, filtration accuracy 1 μm Water introduction port (7) obtained by introducing new ion exchange water from outside the system to the introduction port (9) in the middle of this pipe (6) via the underwater particle removal device and the ion exchange device. ) With a capacity of 50m ³ A polyethylene terephthalate chip was continuously water-treated using a tower-type treatment tank shown in FIG.

  The solid-state polymerized PET chip is processed by a vibration sieving process and an airflow classification process, and the fine and film content is about 15 ppm (the peak temperature on the highest melting peak temperature of fine is 248 ° C), and then continuously fed from the supply port (1) at the top of the treatment tank controlled at a treatment water temperature of 95 ° C, and the discharge port at the bottom of the water treatment tank in 3 hours of water treatment time Water treatment was performed while continuously removing the PET chip from (3) together with the treated water. The introduced water collected before the ion exchange water inlet (9) of the treatment apparatus has a particle content of 1 to 25 μm in particle size of about 1900/10 ml, a sodium content of 0.03 ppm, and a magnesium content of 0.1. 02 ppm, calcium content 0.01 ppm, silicon content 0.07 ppm, and the number of particles having a particle diameter of 1 to 40 μm of recycled water after treatment in the filtration device (5) and the adsorption tower (8) is about 18000. Pieces / 10 ml.

  After the water treatment, it was continuously dried with heated dry air, and subsequently treated in a vibration sieving step and an airflow classification step to remove fines and film-like substances, and the total content was about 20 ppm. The peak temperature on the highest side of the melting peak temperature of this fine was 250 ° C.

In a part of the transportation pipe made of SUS304 connected to the transportation container filling step installed after the airflow classification step, linear low density polyethylene (MI = about 0.9 g / 10 minutes, density = about 0.923 g / cm ³ ) While dropping the inside of a vertical pipe connected to a contact device with three rods with a diameter of about 1 cm and a length of about 20 cm attached at a processing rate (ton / hour) of about 4 tons / hour The PET chip was made to collide with the polyethylene rod at a speed of about 5 km / hour for contact treatment. The ratio A of the surface area (cm ² ) of the PE bar to the throughput per unit time (ton / hour) of the polyester was about 47. After the contact treatment, it was further treated in an airflow classification process.

The obtained PET has an intrinsic viscosity of 0.74 deciliter / gram, a DEG content of 2.8 mol%, a cyclic trimer content of 0.30 wt%, and a cyclic trimer increase of 0.06 wt. %, The average density was 1.4030 g / cm ³ , the AA content was 2.9 ppm, the fine content was about 25 ppm, and the polyethylene content was about 12 ppb.

  In addition, as air for sending solid-phase polymerized PET chips to the subsequent steps and dehumidifying air for drying, an air cleaner equipped with a filter unit made of PET nonwoven fabric of type 3 of JIS B 9908 (1991) and JIS B 9908 ( 1991), air filtered with an air purifier equipped with a HEPA filter unit of type 1 with a particle collection rate of 99% or more (number of particles having a particle size of 0.3 to 5 μm is 530 particles / cubic foot) was used. .

This PET was evaluated using a molded plate and a biaxially stretched bottle. The results are shown in Table 1.
The haze of the molded plate is 4.4%, the molded plate haze spot is 0.1%, Tc1 is 165 ° C., the density of the plug portion is 1.379 g / cm ³ , and the plug portion density deviation is 0.001 g / cm ^3. The transparency of the bottle was as good as 1.0%.

  In addition, there was no problem in the contents leakage test, and there was no deformation of the plug part. The AA content of the bottle was 15.3 ppm, which was a problem-free value. Although 5000 or more continuous stretch blow moldings were carried out, no mold contamination was observed, and the transparency of the bottles was good.

  Chip transportation in the melt polycondensation process, solid-phase polymerization process and water treatment, and chip transportation in the drying process are all carried out by a plug-type transportation system and a partial bucket-type conveyor-transport system, and from a solid-phase polymerization reactor. A screw type feeder was used for all extraction. The chip transportation in the following examples and comparative examples was also performed in the same manner.

(Example 3)
The same equipment as in Example 2 without water treatment after the PET after solid-phase polymerization obtained in Example 2 was treated in a vibration sieving step and an airflow classification step to remove fine and film-like materials. And a contact treatment with polyethylene and a removal treatment of fines and the like by the method and method.
The results are shown in Table 1. The results of the haze of the molded plate, the haze of the bottle, the haze spots, the thickness spots, and the content leakage test were satisfactory. Although 5000 or more continuous stretch blow moldings were carried out, no mold contamination was observed, and the transparency of the bottles was good.

Example 4
The same equipment as in Example 2 without water treatment after the PET after solid-phase polymerization obtained in Example 2 was treated in a vibration sieving step and an airflow classification step to remove fine and film-like materials. And a contact treatment with polyethylene and a removal treatment of fines and the like by the method and method. However, the contact treatment was performed by colliding with the polyethylene rod at a speed of about 25 km / hour.
The results are shown in Table 1. The results of the haze of the molded plate, the haze of the bottle, the haze spots, the thickness spots, and the content leakage test were satisfactory. Although 5000 or more continuous stretch blow moldings were carried out, no mold contamination was observed, and the transparency of the bottles was good.

(Example 5)
After the solid-phase polymerization PET obtained in Example 2 was processed in the vibration sieving step and the airflow classification step to remove fine and film-like substances, the water treatment was not performed, The inside of a vertical pipe connected to a part of a gravity transport pipe made of SUS304 that is connected to the installed container filling process for transportation, with a contact device in which 15 rods made of nylon MXD6 having a diameter of about 2 cm and a length of about 20 cm are attached. While being dropped at a treatment rate per unit time (ton / hour) of about 10 tons / hour, the nylon MXD6 rod was made to collide with the nylon MXD6 at a speed of about 5 km / hour for contact treatment. The ratio A was about 188. After the contact treatment, it was further treated in an airflow classification process.

Nylon MXD6 was produced by heating an aqueous solution of metaxylylenediamine and adipic acid salt under pressure and normal pressure, and polycondensing in a molten state while removing water and water generated by the polycondensation reaction. The relative viscosity (measured at 20 ° C. of a solution in which 0.25 g was dissolved in 25 ml of 96% sulfuric acid) was about 1.8.
The PET obtained had an intrinsic viscosity of 0.74 deciliter / gram, a DEG content of 2.8 mol%, a cyclic trimer content of 0.30 wt%, an average density of 1.4030 g / cm ³ , AA The content was 2.9 ppm, the fine content was about 25 ppm, and the fine melting point was 248 ° C.

This PET was evaluated using a molded plate and a biaxially stretched bottle.
Haze is 5.6% of the forming plate, Tc1 is 160 ° C., mouth density of the plug portion is 1.381g / cm ^3, the spout unit density deviation of no value problem and 0.001 g / cm ^3, the bottle The transparency was also good at 1.5%.
In addition, there was no problem in the contents leakage test, and there was no deformation of the plug part. The AA content of the bottle was 12.0 ppm, which was a satisfactory value. Although 5000 or more continuous stretch blow moldings were carried out, no mold contamination was observed, and the transparency of the bottles was good.

(Comparative Example 1)
After melt polycondensation, the fines removal process before and after the contact treatment with the polyethylene rod-like body is omitted, the fines etc. are not removed, and the speed of the PET chip colliding with the polyethylene rod is reduced. PET was produced in the same manner as in Example 2 except that the speed was changed to 70 km / hour. The peak temperature on the highest temperature side of the melting peak temperature of the fine contained in this PET was 276 ° C.

Table 1 shows the characteristics of the obtained PET, the molded plate formed from the PET, and the biaxially stretched bottle.
The obtained PET has an intrinsic viscosity of 0.74 deciliter / gram, a DEG content of 2.9 mol%, a cyclic trimer content of 0.30 wt%, an average density of 1.4030 g / cm ³ , AA The content was 2.8 ppm, and the fine content was about 5900 ppm.
There was a problem with the haze of the molded plate, the haze spots of the molded plate and the transparency of the bottle, the crystallization rate of the plug portion was too fast, and leakage of the content was observed in the content leakage test.

(Comparative Example 2)
PET was produced in the same manner as in Example 2 except that the speed of the PET chip colliding with the polyethylene rod was changed. The peak temperature on the highest side of the melting peak temperature of the fine contained in this PET was 250 ° C.
Table 1 shows the characteristics of the obtained PET, the molded plate formed from the PET, and the biaxially stretched bottle.
The obtained PET has an intrinsic viscosity of 0.74 deciliter / gram, a DEG content of 2.9 mol%, a cyclic trimer content of 0.30 wt%, an average density of 1.4030 g / cm ³ , AA The content was 2.9 ppm, and the fine content was about 25 ppm.
There was a problem with the haze of the molded plate, the haze spots of the molded plate and the transparency of the bottle, the crystallization rate of the plug portion was too fast, and leakage of the content was observed in the content leakage test.

  In the polyester manufacturing method of the present invention, when the polyester chip contacts at least one member selected from the group consisting of a polyolefin resin member, a polyamide resin member, a polyacetal resin member, and a polybutylene terephthalate resin member. Since the processing is performed while maintaining the speed within the above range, a hollow molded article having good transparency, no transparent spots and thickness spots, excellent heat-resistant dimensional stability, and proper crystallization of the plug portion is formed. be able to. In addition, mold contamination is reduced in sheet molding, bottle molding, and the like, and a large number of molded articles can be easily molded for a long time with excellent transparency. This is because the blending amount of the thermoplastic resin into the PET chip is in an appropriate range and the blending amount is less varied, so that the properties such as transparency of the obtained molded body are improved.

Plan view of the stepped molded plate used in the examples Side view of the stepped molded plate of FIG. It is the schematic of the water treatment apparatus used in the Example.

Explanation of symbols

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

Claims (2)

A polyester chip mainly obtained from an aromatic dicarboxylic acid component and a glycol component is at least one selected from the group consisting of polyolefin resin members, polyamide resin members, polyacetal resin members, and polybutylene terephthalate resin members. In the manufacturing method of polyester made to contact-process with the member of this, the speed | rate of the said polyester chip at the time of contacting the said member is 50 km / hr or less, The manufacturing method of polyester characterized by the above-mentioned. ^2. The polyester production according to claim 1, wherein a ratio A between a surface area (cm ² ) of the member and a contact treatment amount (ton / hour) of the polyester chip per unit time satisfies the following formula. Method.
A = [surface area of the member (cm ² )] / [contact processing amount of the polyester chip per unit time (ton / hour)]
= 6 to 5000

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