JP2000034396A - Production of molding product of thermoplastic polyester resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject molding product of improved transparency having excellent moldability, capable of controlling reduction in transparency in molding by molding a composition prepared by adding an amorphous thermoplastic resin to a specific polyethylene terephthalate in a specific ratio into a sheetlike form. SOLUTION: (A) A polyethylene terephthalate-based resin comprising repeating units composed of <=80 mol.% ethylene terephthalate unit is melted and mixed with (B) >=1 ppb and <10,000 ppm amorphous thermoplastic resin (preferably a polycarbonate-based resin, a polyarylate-based resin or a polystyrene-based resin) to give a thermoplastic polyester resin composition. The composition is molded into a sheet, which is molded to give a thermoplastic polyester resin molding product. Consequently the molding product having excellent moldability and suppressed reduction in transparency in molding and excellent transparency can be expected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a thermoplastic polyester resin thermoformed article, and more particularly, to a thermoformed article which is excellent in thermoformability and suppresses a decrease in transparency during thermoforming. The present invention relates to a method for producing a thermoplastic polyester resin thermoformed article from which a molded article can be obtained.

[0002]

2. Description of the Related Art Conventionally, thermoplastic polyester resins typified by polyethylene terephthalate resin have excellent mechanical properties and chemical properties, as well as excellent transparency, gas barrier properties, safety and health, and the like. The extruded sheet has been thermoformed into trays, containers and the like, and has shown remarkable growth especially in the food packaging field.

[0003] However, these thermoformed articles made of polyethylene terephthalate-based resin undergo crystallization due to heating during thermoforming due to the low crystallization temperature of the polyethylene terephthalate-based resin, and the resulting thermoformed article is obtained. There is a disadvantage that the transparency is inferior, on the other hand, to increase the crystallization temperature of the polyethylene terephthalate resin, to suppress the decrease in transparency during thermoforming, a method of copolymerizing the resin, or Amorphous thermoplastic resin from 1 to
20% by weight (for example, see JP-A-3-2077).
See No. 50 publication. However, in the former method, not only the transparency as a thermoformed body is not yet sufficient, but also the heat resistance is lowered, and in the latter method, the study by the present inventors is considered. According to this, the transparency of the sheet itself comprising the compound is not always excellent,
In addition, it has been found that there is a problem that the transparency as a thermoformed article cannot be improved to a satisfactory degree and the thermoformability is also reduced.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned prior art, and is a thermoformed article which is excellent in thermoformability and suppresses a decrease in transparency during thermoforming and has excellent transparency. It is an object of the present invention to provide a method for producing a thermoplastic polyester resin thermoformed article capable of obtaining the following.

[0005]

DISCLOSURE OF THE INVENTION The present invention has been made to achieve the above object. That is, the present invention provides a polyethylene terephthalate-based resin in which an ethylene terephthalate unit accounts for at least 80 mol% of a constitutional repeating unit. A method for producing a thermoformed thermoplastic polyester resin article, which comprises thermoforming a sheet made of a thermoplastic polyester resin composition containing 1 ppb or more and less than 10,000 ppm of an amorphous thermoplastic resin.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, a polyethylene terephthalate resin as a thermoplastic polyester resin mainly comprises a dicarboxylic acid unit mainly composed of terephthalic acid or an alkyl (about 1 to 4 carbon atoms) ester thereof and ethylene glycol. A polycondensate with a glycol unit as a component, wherein the ethylene terephthalate unit accounts for 80 mol% or more of the constitutional repeating unit;
Preferably, it accounts for at least mol%. If the ethylene terephthalate unit is less than 80 mol%, the mechanical properties and heat resistance of the thermoformed article will be poor.

The dicarboxylic acid units other than terephthalic acid and its alkyl ester include, for example, phthalic acid,
Isophthalic acid, 4,4′-diphenyldicarboxylic acid,
4,4′-diphenoxyethanedicarboxylic acid, 4,4 ′
-Diphenyl ether dicarboxylic acid, aromatic dicarboxylic acid such as 4,4'-diphenyl sulfone dicarboxylic acid, 2,6-naphthalenedicarboxylic acid, alicyclic dicarboxylic acid such as hexahydroterephthalic acid, hexahydroisophthalic acid, malonic acid, succinic acid Acid, adipic acid, azelaic acid,
One or more kinds of aliphatic dicarboxylic acids such as sebacic acid, and as a glycol unit other than ethylene glycol, for example, propylene glycol, trimethylene glycol, tetramethylene glycol, pentamethylene glycol, hexamethylene glycol, decamethylene glycol , Neopentyl glycol, aliphatic glycols such as diethylene glycol, alicyclic glycols such as 1,1-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, 4,4′-dihydroxybiphenyl, 2,2-bis (4 ′ Aromatic glycos such as -hydroxyphenyl) propane, 2,2-bis (4'-β-hydroxyethoxyphenyl) propane, bis (4-hydroxyphenyl) sulfone, bis (4-β-hydroxyethoxyphenyl) sulfonic acid One or more of
Further, for example, hydroxycarboxylic acids and alkoxycarboxylic acids such as p-hydroxybenzoic acid and p-β-hydroxyethoxybenzoic acid, and monofunctional components such as stearic acid, benzoic acid, stearyl alcohol and benzyl alcohol, and trimellitic acid , Pyromellitic acid, trimethanol ethane, trifunctional or higher polyfunctional components such as pentaerythritol, or one or more of such functional components may be used as a copolymerization component, and the dicarboxylic acid unit is isophthalic acid. Acids and the like and diethylene glycol, 1,4-cyclohexanedimethanol and the like as glycol units are preferred. These are each preferably 15
It is used within the range of mol% or less, more preferably within 5 mol%.

The raw materials containing these dicarboxylic acid units containing terephthalic acid or its alkyl ester as a main component, and glycol units containing ethylene glycol as a main component,
In a conventional manner, in the presence of an esterification catalyst or a transesterification catalyst such as a metal compound such as a manganese compound, 240 to
After performing an esterification reaction or a transesterification reaction at a temperature of about 280 ° C. and a pressure of about 1 to ³ kg / cm ² G to obtain bis (β-hydroxyethyl) terephthalate and / or an oligomer thereof, an antimony compound, a germanium compound In the presence of a polycondensation catalyst such as a metal compound such as a metal compound and a stabilizer such as a phosphoric acid compound such as phosphoric acid, a polymer is obtained by performing melt polycondensation at a temperature of about 250 to 300 ° C. and a pressure of about 500 to 0.1 mmHg, After being extracted in a strand form from the extraction port provided at the bottom of the melt polycondensation tank,
It is cut into a chip by a cutter, and the chip polymer obtained by melt polycondensation is usually 120 to
After being pre-crystallized by heating at a temperature of about 200 ° C. for 1 minute or more, under a flow of inert gas such as nitrogen, 190
Temperature of ~ 230 ° C, 1kg / cm ² G ~ 10mmH
Solid-state polymerization is performed at a pressure of about g for 1 to 50 hours to obtain a chip-shaped polyethylene terephthalate-based resin.

In the present invention, the polyethylene terephthalate resin has an intrinsic viscosity of 0.6 to 1.3 dl / g measured at 30 ° C. in a phenol / tetrachloroethane (weight ratio: 1/1) mixed solvent. Are preferable, and those in the range of 0.65 to 1.1 dl / g are more preferable.

In the present invention, examples of the amorphous thermoplastic resin contained in the polyethylene terephthalate resin include a polycarbonate resin, a polyarylate resin, a polystyrene resin, an acrylic resin, a polyphenylene ether resin, and a polyphenylene ether resin. Sulfone-based resins, polyethersulfone-based resins, polyetherimide-based resins, polyamide imide-based resins, and the like, among which polycarbonate-based resins, polyarylate-based resins, and polystyrene-based resins are preferable, and these alone, Alternatively, two or more kinds are used in combination.

The polycarbonate resin may be obtained by either the phosgene method of reacting a dihydroxydiaryl compound with phosgene or the transesterification method of reacting a dihydroxydiaryl compound with a carbonate such as diphenyl carbonate. Further, it may be a homopolymer composed of one kind of dihydroxydiaryl compound or a copolymer composed of two or more kinds of dihydroxydiaryl compounds.

Here, as the dihydroxydiaryl compound, for example, bis (4-hydroxyphenyl) methane, 1,1-bis (4'-hydroxyphenyl) ethane, 2,2-bis (4'-hydroxyphenyl) propane , 2,2-bis (4'-hydroxy-3'-methylphenyl) propane, 2,2-bis (4'-hydroxyphenyl) butane, 2,2-bis (4'-hydroxyphenyl) octane, bis ( Bis (hydroxyaryl) alkanes such as 4-hydroxyphenyl) phenylmethane, 1,1-bis (4′-hydroxyphenyl) cyclopentane, 1,1-bis (4′-hydroxyphenyl)
Bis (hydroxyaryl) cycloalkanes such as cyclohexane, dihydroxydiaryl ethers such as 4,4′-dihydroxydiphenyl ether, 4,4′-dihydroxy-3,3′-dimethyldiphenyl ether, 4,4′-dihydroxydiphenyl ketone; 4,
Dihydroxydiaryl ketones such as 4'-dihydroxy-3,3'-dimethyldiphenylketone, 4,4'-
Dihydroxydiaryl sulfides such as dihydroxydiphenyl sulfide and 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfide; 4,4'-dihydroxydiphenyl sulphoxide; 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulphoxide And dihydroxydiarylsulfoxides such as 4,4′-dihydroxydiphenylsulfone and 4,4′-dihydroxy-3,3′-dimethyldiphenylsulfone.
2-bis (4'-hydroxyphenyl) propane is preferred, and a homopolymer thereof is more preferred. Such a polycarbonate resin has a viscosity average molecular weight of 12,000.
~ 50,000 are preferred.

The polyallylate resin is a polycondensate of an aromatic dicarboxylic acid compound or a derivative thereof and a bisphenol compound or a derivative thereof. Examples of the aromatic dicarboxylic acid compound include phthalic acid,
In addition to isophthalic acid and terephthalic acid, the same as those described in the polyethylene terephthalate-based resin may be used. Among them, a combination of isophthalic acid and terephthalic acid is preferable, and as the bisphenol compound, the polyethylene terephthalate is used. Other than the same ones as those mentioned in the base resin and the polycarbonate base resin, for example, 1,1-bis (4′-hydroxyphenyl)-
2,2,2-trichloroethane, 4,4′-dihydroxy-3,3′-dichlorodiphenyl ether and the like, among which 2,2-bis (4′-hydroxyphenyl)
Propane is preferred. The intrinsic viscosity of such a polyarylate resin is usually in the range of 0.4 to 1.1 dl / g.

Examples of the polystyrene resin include α-substituted alkyl styrenes such as styrene, α-methyl styrene and α-ethyl styrene, m-methyl styrene, p-methyl styrene and 2,5-dimethyl styrene. Examples include homopolymers or copolymers of nuclear-substituted halogenated styrenes such as nuclear-substituted styrene, p-chlorostyrene, p-bromostyrene, and dibromostyrene. Among them, homopolymers of styrene are preferable.

In the present invention, the thermoplastic polyester resin composition comprising the polyethylene terephthalate-based resin and the amorphous thermoplastic resin may have a content of the latter amorphous thermoplastic resin of 1 ppb or more and less than 10,000 ppm. It is essential, and preferably 10 ppb to 7000 ppm, and more preferably 100 ppb to 4000 ppm. When the content of the amorphous thermoplastic resin is less than the above range, it is difficult to suppress a decrease in transparency in thermoforming a sheet molded from the composition to form a thermoformed body, and as a result, Transparency becomes inferior, on the other hand, above the range, the transparency of the sheet itself molded from the composition is not necessarily excellent,
In addition, the effect of improving the transparency of the thermoformed article becomes insufficient, and the thermoformability is also reduced.

In the production of the thermoplastic polyester resin composition of the present invention, a method of directly adding and melting and kneading the above-mentioned amorphous thermoplastic resin to the above-mentioned polyethylene terephthalate-based resin so that the content is within the above-mentioned range, Alternatively, in addition to a conventional method such as a method of adding and melting and kneading as a master batch, the amorphous thermoplastic resin may be used in the step of producing the polyethylene terephthalate-based resin, for example, during melt polymerization (raw material, slurry, catalyst, etc.) , Directly after melt polymerization, immediately after pre-crystallization, during solid-phase polymerization, immediately after solid-phase polymerization, etc. Either add, or contact a liquid such as water dispersed as a powder with a polyester resin chip, or mix a gas such as air mixed as a powder with a polyester. After mixed by a method such as contacting the Le resin chip-shaped body, it is also possible by a method in which melt kneading. In the latter method, at the time of pneumatic transportation of the chip-like body after melt polycondensation of the polyester resin to the pre-crystallization machine,
Or, at the time of pneumatic transportation to the solid-state polymerization tank, or at the time of pneumatic transportation of the chip-like body after the solid-phase polymerization to the storage tank, or at the time of pneumatic transportation to the molding machine, the air for the pneumatic transportation is amorphous. A method in which a thermoplastic resin is mixed is preferable.

In the present invention, the thermoplastic polyester resin composition contains an antioxidant, an ultraviolet absorber, an antistatic agent, a coloring agent such as a dye or a pigment, glass fiber, flica, mica, carbon fiber, titanium fiber and the like. Reinforcing agent such as acid potassium fiber, organic fine particles such as silicone resin having a particle diameter of about 0.01 to 10 μm, and antiblocking agent for inorganic fine particles such as calcium carbonate, barium sulfate, titanium oxide, aluminum oxide, silica, kaolin, clay, etc. , An inorganic or organic nucleating agent, a plasticizer, a flame retardant, a flame retardant auxiliary, and the like.

In the present invention, the method for forming a sheet from the thermoplastic polyester resin composition is not particularly limited. For example, using a single-screw or twin-screw extruder,
Cylinder temperature 240-330 ° C, screw rotation speed 4
It is melt-extruded into a sheet under the conditions of 0 to 300 rpm and the like, and if necessary, pressure-bonded with a touch roll, etc.
It is performed by cooling and solidifying on a cooling drum set at 0 ° C, preferably 25 to 60 ° C.

In the present invention, the average thickness of the sheet is as follows:
Usually in the range of 0.1 to 10 mm, 0.2 to 10 m
m, more preferably 0.5 to 10 mm. If the thickness of the sheet is less than the above range, heat resistance tends to be inferior as a thermoformed body,
Exceeding the above range tends to result in poor thermoformability.

The intrinsic viscosity of the thermoplastic polyester resin composition in the sheet is 0.6 to 1.3 dl / g.
And preferably 0.65 to 1.1 dl / g.
Is more preferably within the range. If the intrinsic viscosity is less than the above range, the thermoformability tends to be inferior, and the mechanical properties of the thermoformed article tend to be inferior. On the other hand, if it exceeds the above range, the sheet itself tends to be difficult to produce. The crystallinity is preferably less than 50%, more preferably 20% or less, particularly preferably 5% or less, as measured by DSC.

In the present invention, the thermoforming of the thermoplastic polyester resin composition sheet is not particularly limited, either.
After preheating to a surface temperature of 0 to 170 ° C., a male plug molding method, a vacuum molding method, a pressure molding method, a vacuum pressure molding method, and a molding method further plug assisted thereto, and a male mold and a female mold are formed. It is performed by shaping into a desired shape at a drawing ratio of 0.2 to 2.0 by a matched mold molding method or the like to be used.

[0022]

EXAMPLES Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to the following examples unless it exceeds the gist. Example 1 86.5 parts by weight of terephthalic acid and ethylene glycol 3
A slurry consisting of 9.0 parts by weight was supplied to a polycondensation tank, and an esterification reaction was carried out at 250 ° C. under normal pressure, and bis (β-hydroxyethyl) terephthalate having an esterification reaction rate of 95% and a low polymer thereof were obtained. After the preparation,
12 parts by weight and 0.025 parts by weight of antimony trioxide were added, and polycondensation was performed at 280 ° C. under a reduced pressure of 1 mmHg.
The produced polymer was drawn out in a strand form from a drawing port provided directly connected to a cooling water tank at the bottom of the polycondensation tank, cooled with water, and then cut into chips to obtain polymer chips. Subsequently, the obtained polymer chip was transferred to a stirring crystallization machine (Bepex), and the surface of the polymer chip was crystallized at 150 ° C., and then dried at 140 ° C. for 3 hours under nitrogen flow, and then allowed to stand still The mixture was transferred to a solid-phase polymerization tower, and subjected to solid-phase polymerization at 210 ° C. for 20 hours under nitrogen flow to produce a chip-like polyethylene terephthalate resin (intrinsic viscosity 0.85 dl / g).

1000 parts by weight of the obtained polyethylene terephthalate resin chip and 2 parts by weight of a polycarbonate resin ("Iupilon H4000" manufactured by Mitsubishi Engineering-Plastics Co., Ltd.) which had been mechanically pulverized to a diameter of 1.5 mm in advance were dried. Blend, 1 in vacuum dryer
After drying at 60 ° C. for 4 hours, it is supplied to an extruder,
A sheet having a thickness of 0.6 mm was formed by melt-extruding a resin at a resin temperature of 290 ° C. into a sheet shape, pressing it on a cooling drum set at 40 ° C. with a touch roll, and cooling and solidifying the sheet.

The transparency of the obtained sheet was evaluated by the following method. Transparency haze meter of sheet ("NDH-300A" manufactured by Nippon Denshoku Co., Ltd.)
And a haze of 10 according to JIS K7105.
20 points were measured for each mm, and 18 points excluding the maximum value and the minimum value were arithmetically averaged and evaluated according to the following criteria. ：: less than 3.0%. Δ: 3.0% or more and less than 4.0%. X: 4.0% or more.

Subsequently, 210 m from the obtained sheet
A sample cut into a size of mx 300 mm was preheated to a surface temperature of 160 ° C. using a radiant heat heater, and then, at a bottom diameter of 50 mm, a mouth diameter of 60 mm, and a depth of 60 mm, a radius was applied to the joint between the bottom and the side wall. It was vacuum-formed with a vacuum-pressure air forming machine having a female mold set at 80 ° C. and having a cup-like shape to produce a thermoformed body.

The obtained thermoformed article was evaluated for thermoformability and transparency by the following methods. Thermoformability The appearance of the surface state, form, and the like of the 20 thermoformed articles was visually observed, and evaluated according to the following criteria. ；: No problem in surface condition and shape of all 20 thermoformed bodies. Δ: 1 to 5 out of 20 thermoformed articles did not have the designed form or had wrinkles or irregularities on the surface. ×: At least 6 out of 20 thermoformed bodies do not have the form as designed or have wrinkles or irregularities on the surface.

Transparency of thermoformed article [0027] The haze of 20 thermoformed articles was measured in the same manner as in the above-mentioned sheet, and the haze was measured by removing the maximum value and the minimum value.
The values of eight samples were arithmetically averaged, and the transparency was evaluated based on the same criteria as described above.

Examples 2 to 5, Comparative Examples 1 to 3 Sheets were formed in the same manner as in Example 1 except that the amount of the polycarbonate resin was changed so as to have the content shown in Table 1. A thermoformed article was manufactured from the obtained sheet, and the transparency of the sheet and the thermoformability and transparency of the thermoformed article were evaluated. The results are shown in Table 1.

Examples 6 and 7 Except that the amount of the polycarbonate resin was changed so as to have the content shown in Table 1 and the thickness of the molded sheet was changed as shown in Table 1, A sheet was formed in the same manner as in Example 1, a thermoformed article was manufactured from the obtained sheet, and the transparency of the sheet and the thermoformability and transparency of the thermoformed article were evaluated. The results are shown in Table 1. Was.

Examples 8-9 Polycarbonate resin ("HH102" manufactured by Mitsubishi Chemical Corporation) was used in place of the polycarbonate resin, and the amount of the resin was changed so as to have the content shown in Table 1. A sheet was formed in the same manner as in Example 1, a thermoformed article was manufactured from the obtained sheet, and the transparency of the sheet and the thermoformability and transparency of the thermoformed article were evaluated. The results are shown in Table 1. Was.

Example 10 Polyethylene terephthalate resin chips obtained in Example 1 were mechanically pulverized to a diameter of 1.5 mm in advance to obtain a polycarbonate resin ("Iupilon H4000" manufactured by Mitsubishi Engineering-Plastics Corporation). .
Using pneumatic transportation air mixed at a rate of 2 g / m ³ ,
After being transferred to the fine powder removing device, by removing excess particles, a polyethylene terephthalate resin chip mixed with polycarbonate resin particles was dried at 130 ° C. for 10 hours in a vacuum drier. Except for supplying the extruder to form a sheet, a sheet is formed in the same manner as in Example 1, and a thermoformed body is manufactured from the obtained sheet. Was evaluated for thermoformability and transparency, and the results are shown in Table 1.

[0032]

[Table 1]

[0033]

According to the present invention, it is possible to produce a thermoformed thermoplastic polyester resin article which is excellent in thermoformability and suppresses a decrease in transparency during thermoforming to obtain a thermoformed article having excellent transparency. A method can be provided.

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Claims (4)

[Claims] 1. A polyethylene terephthalate-based resin in which an ethylene terephthalate unit occupies 80 mol% or more of a repeating constitutional unit, comprises an amorphous thermoplastic resin in an amount of 1 ppb or more.
A method for producing a thermoformed thermoplastic polyester resin article, comprising thermoforming a sheet comprising a thermoplastic polyester resin composition containing less than 0000 ppm. 2. The method according to claim 1, wherein the amorphous thermoplastic resin is a polycarbonate resin. 3. The method for producing a thermoformed thermoplastic polyester resin article according to claim 1, wherein the amorphous thermoplastic resin is a polyarylate resin. 4. The method according to claim 1, wherein the amorphous thermoplastic resin is a polystyrene resin.