JP3362013B2 - High viscosity polyethylene naphthalate resin, method for producing the same, and molded article made therefrom - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a polyethylene naphthalate (hereinafter abbreviated as PEN) resin, and more specifically, a material such as a bottle, which has a high intrinsic viscosity and is capable of obtaining a molded product with less foreign matter. PE suitable as
The present invention relates to an N resin, a method for producing the N resin, and a molded article made of the same.

[0002]

2. Description of the Related Art PEN resin is superior to polyethylene terephthalate (hereinafter abbreviated as PET) resin in basic physical properties such as heat resistance, gas barrier property and chemical resistance. It is useful as a packaging material for bottles (containers), sheets, films, etc., and many proposals have been made. Among packaging materials, resins used for bottles such as juices and cosmetics are strongly required to have a small amount of foreign matter from the viewpoint of commercial value. The PEN resin can be manufactured basically by the same method as that of the PET resin, and it is proposed to carry out solid phase polymerization when a high intrinsic viscosity such as a bottle is required. (JP-A-7-18068, JP-A-9-778
59, JP-A-10-218979, etc.).

However, in the case of PEN resin, 210
If solid phase polymerization is carried out at a high temperature of ℃ or more for a long time, there is a problem that a part of the resin has a high melting point. Therefore, when the resin after solid-phase polymerization is melted and molded, the part having a high melting point is not melted and is mixed as a foreign matter in the molded product. Therefore,
Molded products such as bottles greatly reduce the product value.

As a method for avoiding this, there is a method of increasing intrinsic viscosity by melt polymerization or a method of carrying out solid phase polymerization at a low temperature of less than 210 ° C. However, the former method increases the viscosity of the resin, When the resin is discharged from the polymerization kettle, not only the amount of resin remaining in the polymerization kettle increases and productivity decreases, but also the polymerization time increases, which deteriorates the color tone of the polymer. In the latter method, solid phase polymerization requires a long time,
Productivity is significantly reduced.

The inventors of the present invention have made earnest studies on a polyethylene naphthalate resin which does not have a high melting point in a part of the resin even when it is solid-state polymerized at high temperature, and has good productivity and good color tone of the resin. The present invention has been achieved by finding a resin having the thermal properties and solubility of

[0006]

DETAILED DESCRIPTION OF THE INVENTION Namely, the present invention is 2,6-naphthalenedicarboxylic acid as a main acid component and ethylene glycol as a main glycol component, further 2,6 na
Acid component other than phthalenedicarboxylic acid component and / or ethylene
0.1 mol of glycol components other than ren glycol
% Or more and less than 2 mol% of a copolymerized polyester, the intrinsic viscosity (IV) of which satisfies the following formula 1 and is observed first when the temperature is raised from 25 ° C. to 10 ° C./min by a differential scanning calorimeter. When the peak temperature of the endothermic peak is 245 ° C. or higher and the compound is dissolved in a mixed solvent of phenol / 1,1,2,2-tetrachloroethane = 60/40 (weight ratio) at a concentration of 1 g / deciliter at 130 ° C. And a polyethylene naphthalate resin characterized by being dissolved within 2 hours, a method for producing the same, and a molded article comprising the same. 0.65 <IV ≦ 1.2 (1)

The present invention will be described in detail below. In the present invention, "2,6-naphthalenedicarboxylic acid" means 2,6
-Naphthalenedicarboxylic acid and its ester-forming derivative (lower alkyl ester such as 2,6-naphthalenedicarboxylic acid dimethyl ester, phenyl ester, acid anhydride, etc.) are targeted.

Further, the PEN resin of the present invention has an IV of 0.
The resin is more than 65 and 1.2 or less. IV = 0.65
When it is below, when producing a molded product such as a bottle, there arise problems such as a drawdown of the resin and a decrease in mechanical strength of the molded bottle. In addition, IV is 1.
When it exceeds 2, the melt viscosity of the resin becomes too high, which not only imposes a load on the molding machine, but also reduces the productivity, which is not preferable. A more preferable range of IV is 0.
It is 7 or more and 0.9 or less.

Further, the PEN resin of the present invention has a peak temperature of an endothermic peak which is first observed when the temperature is raised from 25 ° C. to 10 ° C./min by a differential scanning calorimeter, which is 245 ° C. or higher. The differential scanning calorimeter referred to here is from 25 ° C to 10
The endothermic peak observed first when the temperature is raised at ℃ / min is the melting point of the resin, or when the resin is heated below the melting point to crystallize or solid-phase polymerize, it depends on the temperature and time. It is an endothermic peak due to a structural change occurring in the resin. The latter endothermic peak temperature increases as the temperature at which the resin is heated increases and as the heating time increases.
If this temperature is less than 245 ° C., the resin IV = 0.6
When it is 5 or more, the resin does not have a good color tone.

Furthermore, the PEN resin of the present invention is phenol / 1,1,2,2-tetrachloroethane = 60/40.
(Weight ratio) in a mixed solvent at a concentration of 1 g / deciliter,
When dissolved at 130 ° C, it dissolves within 2 hours. If the resin is not melted under these conditions, if the resin is melted and molded, the part having a high melting point is not melted and is mixed in the molded product as a foreign matter.

The PEN resin of the present invention contains 2,6-
The acid component other than naphthalenedicarboxylic acid and / or the glycol component other than ethylene glycol is 0.1 to 10 mol%, preferably 0.1 mol% with respect to the total of all acid components or the total of glycol components contained in the resin.
It is preferably 5 mol% or less and particularly preferably 0.1 mol% or more and less than 2 mol%. 0.
If it is less than 1 mol%, the intrinsic viscosity (IV) is 0.65.
When a resin having a peak temperature of 245 ° C. or higher of the endothermic peak first observed when the temperature is raised from 25 ° C. by a differential scanning calorimeter at 10 ° C./min, a part of the resin has a high melting point. If the resin is melted and molded, the high melting point portion is not melted and there is a high possibility that it will be mixed into the molded product as a foreign substance. Further, when it exceeds 10 mol%, the crystallinity of the polymer is lowered, so that solid phase polymerization becomes difficult, and it is difficult to produce a resin having an IV of more than 0.65. In order to suppress the deterioration of the crystallinity of the resin and the decrease of the melting point of the polymer to maintain the heat resistance of the resin, 2,6
-The copolymerization ratio of the acid component other than naphthalenedicarboxylic acid and / or the glycol component other than ethylene glycol is
Preferably 5 mol% or less, particularly preferably 2 mol%
Is less than.

The acid component other than 2,6-naphthalenedicarboxylic acid is not particularly limited, but for example, oxalic acid, malonic acid, succinic acid, adipic acid, sebacic acid,
Aliphatic dicarboxylic acids such as dodecanedicarboxylic acid; also terephthalic acid, isophthalic acid, 4,4'-diphenyldicarboxylic acid, diphenoxyethane-4,4'-dicarboxylic acid, diphenylsulfone-4,4'-dicarboxylic acid, diphenyl ether Aromatic dicarboxylic acids such as -4,4'-dicarboxylic acid; alicyclic dicarboxylic acids such as hexahydroterephthalic acid, decalin dicarboxylic acid, tetralin dicarboxylic acid, 1,4-cyclohexanedicarboxylic acid; dimer acid, glycolic acid, p -Oxyacids such as oxybenzoic acid. Among these, terephthalic acid and isophthalic acid are preferable in terms of cost. These acid components are also applicable to ester-forming derivatives thereof (lower alkyl esters such as dimethyl ester, phenyl ester, acid anhydride, etc.).

The glycol component other than ethylene glycol is not particularly limited in the same manner as the acid component,
Aliphatic diols such as tetramethylene glycol, propylene glycol, 1,3-butanediol, neopentyl glycol; alicyclic diols such as 1,4-cyclohexanedimethanol and tricyclodecanedimethylol; bisphenol A, bisphenol S, Examples thereof include aromatic diols such as tetrabromobisphenol A and ethylene oxide adducts thereof, dimer diols and ethylene oxide adducts thereof. Among these, tetramethylene glycol, neopentyl glycol, 1,4-cyclohexanedimethanol, bisphenol A and bisphenol S, and their ethylene oxide adducts are preferable.

Further, the PEN resin of the present invention may contain other resins and various additives, if necessary. For example, polyester resins such as polyethylene terephthalate, heat stabilizers such as calcium acetate, magnesium acetate, manganese acetate, germanium dioxide, antimony trioxide, trimethyl phosphate, etc. used as catalysts and for preventing by-products such as diethylene glycol. Examples thereof include ammonium salts such as hydroxytetraethylammonium, inorganic lubricants and organic lubricants for improving the slipperiness of the molded article, antioxidants, antistatic agents, weathering agents and the like.

The PEN resin of the present invention can be produced by using a general polyester melt polymerization method such as a known transesterification method or direct polymerization method. For example, there is a method in which an ester exchange reaction is performed using an alkyl ester of a dicarboxylic acid and a diol, or an esterification reaction is performed using a dicarboxylic acid and a diol under a nitrogen stream, and then polycondensation is performed at high temperature and reduced pressure.

Further, in order to produce the high-viscosity PEN resin of the present invention, it is necessary to crystallize and solid-phase polymerize the polyester produced by the melt polymerization method. As the crystallization and solid phase polymerization methods, general polyester crystallization and solid phase polymerization methods are used. For example, a method may be mentioned in which the resin is heated to a temperature of 150 ° C. to 200 ° C. to be crystallized, and then solid phase polymerization is carried out at a temperature lower than the melting point thereof under reduced pressure or a nitrogen stream. However, the solid phase polymerization needs to be performed at 210 ° C. or higher and for 12 hours or longer. If the temperature is lower than 210 ° C., the solid phase polymerization time becomes too long and the color tone is good IV =
A resin having a high viscosity exceeding 0.65 cannot be obtained.
Further, even if the solid-phase polymerization time is less than 12 hours, it is impossible to obtain a high-viscosity resin having a good color tone of IV = 0.65 or more.

The method for obtaining a molded product such as a container or a bottle from the PEN resin of the present invention is not particularly limited, and a conventionally known method can be used. For example, as a method of manufacturing a bottle, a method of supplying the PEN resin of the present invention to an injection molding machine to mold a preform, and heating and blow molding the preform can be mentioned. Examples of the method for producing a molded article such as a container include a method in which the PEN resin of the present invention is supplied to an extruder and extruded through a T die to produce a sheet, and the sheet is thermoformed.

[0018]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. The measurement and evaluation methods are shown below.

(1) Phenol / resin soluble resin at a concentration of 1 g / deciliter
When dissolved in a mixed solvent of 1,1,2,2-tetrachloroethane = 60/40 (weight ratio) at 130 ° C. for 2 hours, the solubility of the resin was visually evaluated. ○: dissolved, ×: undissolved

(2) IV resin is phenol / 1,1,2,2-tetrachloroethane = 60/4 at a concentration of 1 g / deciliter, 0.6 g / deciliter and 0.3 g / deciliter, respectively.
It is dissolved in a mixed solvent of 0 (weight ratio), and the specific viscosity (η _SP ) at each concentration (C) is determined with an Ubbelohde viscometer at 20 ° C. Then, η _SP / C was plotted against C and extrapolated to zero concentration from the obtained straight line to obtain it.

(3) Endothermic peak temperature This is the peak temperature observed first when about 10 mg of the resin is put into DSC7 manufactured by Perkin Elmer Co., Ltd. and the temperature is raised from 25 ° C. at a heating rate of 10 ° C./min.

(4) The unmelted resin is supplied to an extruder and extruded from a T die at 290 ° C. to prepare a sheet, and when a tray is formed from this sheet by thermoforming, the tray bottom 100 cm ²
The number of foreign matters contained therein was visually evaluated. ○: 1 or less, △: 2 to 5, ×: 5 or more

Example 1 A stainless steel autoclave was charged with 242 parts by weight of 2,6-dimethylnaphthalate, 2 parts by weight of dimethyl terephthalate and 137 parts by weight of ethylene glycol, and then calcium acetate monohydrate 0.1 as an ester exchange catalyst.
1 part by weight was added, and further cobalt acetate tetrahydrate 0.01
By weight part, transesterification reaction was carried out. After the completion of the transesterification reaction, 0.002 part by weight of hydroxytetraethylammonium and 0.11 part by weight of trimethyl phosphate were added, and then 4.24 parts by weight of a 0.8 wt% aqueous solution of germanium dioxide as a polymerization catalyst (0.2% by weight as germanium dioxide. (03 parts by weight) was added, and a polycondensation reaction was performed at 290 ° C. under reduced pressure. Then, the pressure was returned to normal pressure, the content was extruded into a gut shape, cooled with water, and a chip-shaped PEN resin (IV = 0.56) was obtained using a cutter. Further, this resin was heated in a vacuum at 160 ° C. for 8 hours for crystallization. Then, this resin was subjected to solid phase polymerization at 220 ° C. for 24 hours in vacuum. When the resin thus obtained was dissolved in a mixed solvent of phenol / 1,1,2,2-tetrachloroethane = 60/40 (weight ratio) at a concentration of 1 g / deciliter at 130 ° C., it was dissolved within 2 hours. And IV is 0.7
It was 5. And with a differential scanning calorimeter from 25 ℃ to 10 ℃
The peak temperature of the endothermic peak that was first observed when the temperature was raised at a rate of / min was 250 ° C. Then, this resin was supplied to an extruder and extruded from a T die at 290 ° C. to form a sheet, and a tray was formed from this sheet by thermoforming. The number of foreign matters contained in the tray bottom 100 cm ² was 0. It was an individual.

Examples 2 to 4 and Reference Examples 1 to 4 PEN resins were obtained in the same manner as in Example 1 except that the composition and solid phase polymerization conditions of the polyester resin were changed as shown in Tables 1 and 2. . The evaluation results are shown in Tables 1 and 2.

Comparative Example 1 A stainless steel autoclave was charged with 244 parts by weight of 2,6-dimethylnaphthalate and 137 parts by weight of ethylene glycol, and then 0.11 part by weight of calcium acetate monohydrate as an ester exchange catalyst was added. Further, 0.01 part by weight of cobalt acetate tetrahydrate was added to carry out a transesterification reaction. After completion of the transesterification reaction, 0.002 parts by weight of hydroxytetraethylammonium and 0.11 parts by weight of trimethyl phosphate were added, and then 4.24 parts by weight of a 0.8 wt% aqueous solution of germanium dioxide as a polymerization catalyst (0.2% as germanium dioxide was used). (03 parts by weight) was added, and a polycondensation reaction was performed at 290 ° C. under reduced pressure. afterwards,
The pressure is returned to normal pressure, the contents are extruded into a gut shape, cooled with water, and a chip-shaped PEN resin (IV = 0.5
6) was obtained. Further, this resin was heated in a vacuum at 160 ° C. for 8 hours for crystallization. Then, in vacuum, 2
Solid phase polymerization was carried out at 20 ° C. for 24 hours. The resin thus obtained was mixed with phenol / 1,1,1 at a concentration of 1 g / deciliter.
It was dissolved in a mixed solvent of 2,2-tetrachloroethane = 60/40 (weight ratio) at 130 ° C., but it was not dissolved even if it was dissolved for 2 hours or more. The peak temperature of the endothermic peak first observed when the temperature of this resin was raised from 25 ° C to 10 ° C / min by a differential scanning calorimeter was 252 ° C. Then, this resin was supplied to an extruder and extruded from a T die at 290 ° C. to form a sheet, and a tray was formed from this sheet by thermoforming.
The number of foreign matters contained in cm ² was as large as 20, which was unsuitable as a molding material.

Comparative Examples 2 and 3 PEN was prepared in the same manner as in Example 1 except that the composition of the polyester resin and the solid phase polymerization conditions were changed as shown in Table 3.
A resin was obtained. Table 3 shows the evaluation results.

Comparative Example 4 208 parts by weight of 2,6-dimethyl naphthalate and 29 parts of dimethyl terephthalate were placed in an autoclave made of stainless steel.
1 part by weight, 137 parts by weight of ethylene glycol were charged, and then calcium acetate monohydrate as an ester exchange catalyst was added.
11 parts by weight of cobalt acetate tetrahydrate 0.0
1 part by weight was added to carry out a transesterification reaction. After the completion of the transesterification reaction, 0.002 part by weight of hydroxytetraethylammonium and 0.11 part by weight of trimethyl phosphate were added, and then 4.24 parts by weight of a 0.8 wt% aqueous solution of germanium dioxide as a polymerization catalyst (0.2% by weight as germanium dioxide. (03 parts by weight) was added, and a polycondensation reaction was performed at 290 ° C. under reduced pressure. Then, the pressure was returned to normal pressure, the content was extruded into a gut shape, cooled with water, and a chip-shaped PEN resin (IV = 0.56) was obtained using a cutter. Further, when this resin was heated in vacuum at 160 ° C. for 8 hours, the resin was fused and solid-phase polymerization could not be performed.

Comparative Example 5 An attempt was made to produce a PEN resin in the same manner as in Comparative Example 1 except that the solid-state polymerization was carried out at 200 ° C. However, even if the polymerization was carried out for 30 hours, the IV was only 0.60 and the solid content was solid. Phase polymerization was terminated. When the polymer was supplied to an extruder and extruded from a T die at 290 ° C. to produce a sheet, a good sheet could not be obtained due to drawdown. Therefore, even if this sheet is thermoformed, a tray having a good appearance cannot be obtained.

[0029]

[Table 1]

[0030]

[Table 2]

[0031]

[Table 3]

As is clear from the above results, the endotherm first observed when the solid phase polymerization is carried out at 210 ° C. or higher for 12 hours or longer and the temperature is raised from 25 ° C. to 10 ° C./min by the differential scanning calorimeter. Even if a resin having a peak peak temperature of 245 ° C. or higher is obtained, it is mixed with a mixed solvent of phenol / 1,1,2,2-tetrachloroethane = 60/40 (weight ratio) at 130 ° C.
If it does not dissolve even if it dissolves for more than a time, a good molded product cannot be obtained because a large amount of unmelted material is included in the melt molding. (Comparative Examples 1 to 3) On the other hand, if solid phase polymerization is performed at a low temperature, it becomes difficult to efficiently produce a resin having an IV of more than 0.65. (Comparative Example 5) Further, when the ratio of the acid component other than 2,6-naphthalenedicarboxylic acid and / or the glycol component other than ethylene glycol exceeds 10 mol%, the crystallinity of the resin decreases, so that crystallization and solidification of the resin occur. Phase polymerization can be performed, IV
It is not possible to obtain a resin having a value of 0.65 or more. (Comparative example 4)

[0033]

EFFECT OF THE INVENTION The PEN resin of the present invention has a high intrinsic viscosity suitable for bottle molding and does not contain a high-melting point material that does not melt during melt molding, so that a molded product having a good appearance can be obtained. .

[Brief description of drawings]

FIG. 1 shows the PEN resin of the present invention in a differential scanning calorimeter of 25
It is an example of an endothermic peak observed when the temperature is raised from 10 ° C to 10 ° C / min.

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-11-106492 (JP, A) JP-A-11-60704 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C08G 63/00-63/91

Claims (4)

(57) [Claims] 1. A 2,6-naphthalenedicarboxylic acid as a main acid component, ethylene glycol as a main glycol component, and a 2,6-naphthalenedicarboxylic acid component as a main component.
External acid component and / or glycos other than ethylene glycol
Of 0.1% or more and less than 2% by mole
A polyester that is, the intrinsic viscosity (IV) satisfies the following formula 1, 10 ° C. from 25 ° C. by differential scanning calorimetry
The peak temperature of the endothermic peak that is first observed when the temperature is raised at 1 / min is 245 ° C. or higher, and phenol / 1,
At a concentration of 1 g / deciliter in a mixed solvent of 1,2,2-tetrachloroethane = 60/40 (weight ratio), 130
A polyethylene naphthalate resin characterized by being dissolved within 2 hours when it is dissolved at a temperature of ℃. 0.65 <IV ≦ 1.2 (1) 2. The polyethylene naphthalate resin according to claim 1, which has been crystallized and solid-phase polymerized. 3. When producing a polyester having 2,6-naphthalenedicarboxylic acid as an acid component and ethylene glycol as a glycol component, an acid component other than 2,6-naphthalenedicarboxylic acid and / or a glycol component other than ethylene glycol is used. Of 0.1 to less than 2 mol% and melt-polymerized.
The method for producing a polyethylene naphthalate resin according to any one of claims 1 to 3, wherein solid phase polymerization is carried out at a temperature of not less than ° C and for not less than 12 hours. 4. A molded product made of polyethylene naphthalate resin according to any one of claims 1-2.