JP2003096169A - Copolyester - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a copolyester containing little foreign material, excellent in transparency and improved in electrostatic adherence. SOLUTION: This copolyester consists of one or more acid components and two or more glycol components, in which one of the glycol components comprises 1,4-cyclohexanedimethanol (CHDM), and the CHDM accounts for 20-80 mol% of the whole glycol components, which contains an alkali metal compound in an amount in terms of metal atoms (M<1> ) satisfying the relation of the formula: 5<=M<1> <=100 ppm, and which contains an alkaline earth metal compound and a phosphorus compound in amounts respectively in terms of alkaline earth metal atoms (M<2> ) and phosphorus atoms (P) satisfying the relation of the formula: 1.2<=M<2> /P<=5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a copolyester which has few foreign matters and is excellent in transparency and electrostatic adhesion. The copolymerized polyester of the present invention can be used not only as a film, a sheet, a decorative board, a building material, etc., but also as a blending component with other polymers such as polyethylene terephthalate (PET).
It is possible to modify the transparency and mechanical properties of other polymers.

[0002]

2. Description of the Related Art Polyester typified by PET has excellent mechanical properties, heat resistance, electrical insulation, chemical resistance, etc., and is therefore widely used as a material for films, sheets, fibers, bottles, engineering plastics, etc. It is used.

Polyester is used in a wide variety of fields such as packaging, photographic materials, electrical appliances, and magnetic tapes, even when used only for films. Usually, a polyester film is obtained by melt-extruding polyester and then stretching it.

In this case, in terms of film quality, uniformity of thickness is a very important characteristic, and how to secure this characteristic, and in terms of productivity, productivity directly depends on casting speed. Therefore, how to increase the casting speed to improve productivity is an important issue.

In order to solve this problem, when the sheet-like material melt-extruded from the extrusion die is rapidly cooled on the surface of the rotary cooling drum, it is necessary to enhance the adhesion between the sheet-like material and the drum surface. Become. As a method of increasing the adhesion between the sheet-like material and the drum surface, a wire-shaped electrode is provided between the extrusion die and the rotating cooling drum to apply a high voltage to cause static electricity to be deposited on the surface of the unsolidified sheet-like material. Then, a method (electrostatic contact casting method) in which the sheet is rapidly cooled while closely contacting with the surface of the cooling body is effective.

To effectively carry out the electrostatic contact casting method,
First of all, it is necessary to enhance the electrostatic adhesion between the sheet-like material and the drum surface. For that purpose, it is important to deposit a large amount of charge on the surface of the sheet-like material. In order to increase the charge amount, it is effective to modify the polyester to lower its specific resistance, and great efforts have been made.

For example, in Japanese Patent Publication No. 3-54129, a specific amount of a sodium or potassium compound and a magnesium compound and a phosphorus compound are adjusted so that the atomic ratio of magnesium atom and phosphorus atom is within a specific range during the production of PET. It is disclosed that the specific resistance is lowered by adding a compound. Further, in the same publication, a magnesium compound,
It is disclosed that by specifying the time of addition of the sodium compound and the phosphorus compound, the foreign matter due to the catalyst is reduced and the quality of the film is improved.

On the other hand, a polyester obtained by copolymerizing 1,4-cyclohexanedimethanol as a glycol component is
As disclosed in Japanese Patent Publication No. 2000-504770, it is noted for its excellent transparency and brightness. However, since the copolyester is also a polyester like PET, the specific resistance is high, and modification for improving electrostatic adhesion is essential from the viewpoint of film quality and productivity. However, when CHDM is copolymerized with PET, the affinity for the catalyst tends to deteriorate, the amount of foreign matter based on the catalyst metal increases, and the electrostatic adhesion becomes difficult to develop. Even if it is adopted as it is, the effect cannot be expected.

[0009]

Therefore, the object of the present invention is not only to use it alone for film, sheet, decorative board, and building material applications, but it is also suitable for modification of other polymers with few foreign substances and is transparent. The object is to provide a copolyester having excellent properties and improved electrostatic adhesion.

[0010]

Means for Solving the Problems The inventors of the present invention have made diligent studies and have investigated the copolymerization ratio of 1,4-cyclohexanedimethanol in the copolyester, the content of alkali metal compounds, and the alkaline earth metal compounds contained therein. Focusing on the phosphorus compound and the atomic ratio, the electrostatic adhesion is significantly improved,
It was found that a copolyester having less foreign matter and excellent transparency can be obtained, and the present invention has been completed.

The present invention is a copolyester composed of one or more kinds of acid components and a plurality of kinds of glycol components, wherein one of the glycol components is 1,4-cyclohexanedimethanol (CHDM). And the copolymerization ratio of 1,4-cyclohexanedimethanol to the total glycol component is in the range of 20 to 80 mol%, and the alkali metal compound is 5 ≦ M ¹ ≦ 100 as the amount of metal atom (M ¹ ).
ppm, and the alkaline earth metal compound and the phosphorus compound are metal atoms (M ² ) of the alkaline earth metal compound.
Ratio of the phosphorus atom (P) of the phosphorus compound and the phosphorus compound (M ² /
P) is a copolyester which is contained so that 1.2 ≦ M ² / P ≦ 5.

The present invention is the above-mentioned copolymerized polyester wherein the main acid component is terephthalic acid and the glycol component contains ethylene glycol. In the present invention, the alkaline earth metal compound has an amount of metal atoms (M ² ) of 40.
The above-mentioned copolyester is contained in ≦ M ² ≦ 400 ppm.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION (Constituent Component of Copolymerized Polyester) One type of glycol component constituting the copolymerized polyester of the present invention is 1,4-cyclohexanedimethanol (hereinafter sometimes referred to as CHDM). It is important that 20 to 80 mol% of all glycol components are CHDM. If the copolymerization ratio of CHDM is out of this range, crystallization of the polyester is likely to occur, and the transparency, which is one of the characteristics of the copolyester of the present invention, decreases. This tendency becomes remarkable as the thickness of molded products such as decorative boards and building materials increases, which is disadvantageous because the use of the copolyester is limited. The desirable copolymerization ratio of CHDM is 23-
78 mol%, more desirable copolymerization ratio is 25 to 75
Mol%. The desired copolymerization ratio of CHDM results in a copolyester having more excellent transparency.

As the glycol component other than CHDM,
Ethylene glycol, 1,3-propylene glycol,
1,4-butylene glycol or the like can be applied. Of these, ethylene glycol is particularly preferable in terms of price and physical properties. Further, a plurality of glycol components other than CHDM may be used.

The acid component constituting the copolyester of the present invention is preferably terephthalic acid or an ester of terephthalic acid, and if necessary, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 1,4-biphenyldicarboxylic acid. Aromatic dicarboxylic acid such as, alicyclic dicarboxylic acid such as 1,4-cyclohexanedicarboxylic acid, adipic acid,
Aliphatic dicarboxylic acids such as sebacic acid can be used.

(Alkali Metal Compound) The copolyester of the present invention contains a trace amount of an alkali metal compound.
The alkali metal compound, when used alone, has a small effect of improving electrostatic adhesion, but when combined with an alkaline earth metal compound and a phosphorus compound described later, electrostatic adhesion is significantly improved.

Although its mechanism of action is not clear, it is considered that electrostatic adhesion can be enhanced by forming a complex with an alkali metal, an alkaline earth metal, a phosphorus compound or an oligomer.

Alkali metal compounds necessary for improving electrostatic adhesion
The content of the substance is the alkali metal atom (M¹) As 5
~ 100 ppm (weight). M¹Is less than 5ppm
When it is full, the effect of improving electrostatic adhesion is small, and conversely 100 ppm
Over M¹Using an amount of alkali metal compound
There is no electrostatic adhesion improvement effect commensurate with the amount used, rather foreign matter
Negative effects such as generation will increase. Of alkali metal compounds
Desirable content is M ¹6-90ppm as the amount of
A desirable content is 7 to 80 ppm. Copolymer poly
The content of alkali metal compound in the ester is
This corresponds to the amount of alkali metal compound added to the reaction system.

Examples of the metal of the alkali metal compound include lithium, sodium and potassium, and examples of the alkali metal compound include hydroxides, acetates, aliphatic carboxylates, carbonates and alkoxides of these metals. To be Specific examples of the alkali metal compound suitable for use include lithium hydroxide, lithium acetate, lithium carbonate,
Sodium hydroxide, sodium acetate, sodium carbonate,
Examples thereof include sodium ethoxide, potassium hydroxide, potassium acetate, potassium carbonate and the like. Of these, it is particularly preferable to use sodium acetate. These alkali metal compounds may be used alone or in combination of two or more.

(Alkaline Earth Metal Compound) The copolyester of the present invention contains a slight amount of alkaline earth metal compound. Alkaline earth metal compounds play an important role in electrostatic adhesion. However, on the other hand, it may cause the generation of foreign matter depending on the amount and the manufacturing conditions, and therefore the formulation should be careful.

The alkaline earth metal compound is an alkali metal
By combining with compounds and phosphorus compounds,
It shows a great improvement effect on the electrical adhesion. Alkaline earth metallization
The content of the compound is the alkaline earth metal atom (M²) Amount and
The range of 40 to 400 ppm (weight) is preferable. M
²If the amount is less than 40 ppm, the effect of improving electrostatic adhesion is small
Conversely, M exceeding 400 ppm²Amount of alkaline earth
Even if a metal compound is used, the electrostatic adhesion property can be adjusted according to the amount used.
Not a good effect, but rather a large negative effect such as foreign substance generation and coloring
I tend to be sick. Desirability of alkaline earth metal compounds
The content is M ²50-350ppm as the amount of
A desirable content is in the range of 60 to 300 ppm. Both
Of alkaline earth metal compounds in polymerized polyester
Content is the amount of alkaline earth metal compound added to the reaction system
Matches

As the metal of the alkaline earth metal compound,
Examples thereof include magnesium, calcium, strontium, barium, and the like, and examples of the alkaline earth metal compound include hydroxides, acetates, aliphatic carboxylates of these metals, and the like. Specific examples of the alkaline earth metal compound suitable for use include magnesium hydroxide, magnesium acetate, calcium acetate, strontium acetate, barium acetate and the like. Of these, use of magnesium acetate is preferred. These alkaline earth metal compounds may be used alone or in combination of two or more.

(Phosphorus Compound) The copolyester of the present invention contains a small amount of a phosphorus compound. The phosphorus compound itself has no effect of improving electrostatic adhesion. However, the electrostatic adhesion is remarkably improved by combining with the alkali metal compound and the alkaline earth metal compound.

Although the reason for this is not clear, the addition of the phosphorus compound in the production of the copolyester reduces the generation of foreign substances, and therefore, the effect of increasing the charge amount is considered. The addition amount of the phosphorus compound in the production of the copolyester is, for example, 60 to 500 as P atom.
ppm (weight), preferably 65 to 450 ppm, more preferably 70 to 400 ppm. If the addition amount of the phosphorus compound is less than 60 ppm as P atom, not only the effect on electrostatic adhesion is small, but also the amount of foreign matter produced tends to increase, which is not preferable. On the contrary, 500 as a P atom
Addition of a phosphorus compound in an amount exceeding ppm does not have the effect of improving electrostatic adhesion or reducing the production of foreign substances commensurate with the amount, but rather promotes the production of diethylene glycol, which is unfavorable to the physical properties of the copolyester. The negative impact tends to increase.

The content of the phosphorus compound in the copolyester is usually smaller than the amount of the phosphorus compound added to the reaction system. The phosphorus compound varies depending on its type and equipment and conditions (temperature, degree of reduced pressure, etc.) of the polycondensation reaction,
During the polycondensation reaction, a part of it was scattered and the added amount was 60-8.
About 5% remains and is contained in the copolyester. For example, under the conditions in this Example described later, about 67% remains in the case of trimethyl phosphate, and about 80% remains in the case of phosphoric acid. Therefore, the amount of the phosphorus compound added to the reaction system may be appropriately determined according to the intended content of the phosphorus compound in the copolyester.

As the phosphorus compound, phosphoric acid, phosphorous acid,
Examples thereof include hypophosphorous acid, phosphonic acid, alkyl- or allyl-substituted phosphonic acid and esters thereof. Specific examples of phosphorus compounds suitable for use include phosphoric acid, trimethyl phosphate, triethyl phosphate, phosphorous acid, hypophosphorous acid, methylphosphonic acid, allylphosphonic acid, and methylphosphonic acid dimethyl ester. Of these, phosphoric acid, trimethyl phosphate, and triethyl phosphate are preferably used. These phosphorus compounds may be used alone or in combination of two or more.

(M ² / P atom number ratio) The copolyester of the present invention comprises an alkaline earth metal compound and a phosphorus compound, a metal atom (M ² ) of the alkaline earth metal compound and a phosphorus atom (P) of the phosphorus compound ( P) and the atomic ratio (M ² / P) of 1.2 ≦ M ² / P ≦ 5. As described above, since a part of the phosphorus compound is scattered during the polycondensation reaction, the above M ² / P is contained in the obtained copolyester.
The amount of the phosphorus compound added to the reaction system is adjusted so that the phosphorus compound is contained in an amount satisfying the above range.

M ² / P is very important for improving electrostatic adhesion and suppressing foreign matter formation. M ² / P is 1.2 ≦ M ²
Within the range of / P ≦ 5, the electrostatic adhesion is improved and the generation of foreign matter is suppressed. When M ² / P is less than 1.2, the electrostatic adhesiveness is significantly reduced. On the other hand, when M ² / P exceeds 5.0, the negative effects are unfavorably large, such as the promotion of foreign substance generation and the unnecessary coloring of the copolyester due to the effect of improving electrostatic adhesion. Desirable M ²
/ P is 1.3 to 4.5, more preferably 1.4 to 4.0.
Is the range.

(Method for producing copolyester) Any conventionally known method can be applied to the production of the copolyester of the present invention. In general, a production process in which a low polymer is first formed by a transesterification reaction or an esterification reaction and then a high polymer is formed by a polycondensation reaction is desirable.

The addition of the alkali metal compound, the alkaline earth metal compound and the phosphorus compound to be contained in the copolyester of the present invention is optional from the time when the raw materials are introduced, after the transesterification reaction or after the end of the transesterification reaction (before the polycondensation reaction). It is possible to carry out at the point of time, but it is desirable to carry out after the completion of the transesterification reaction from the viewpoint of suppressing the generation of foreign matter due to the metal compound.

As the production equipment, conventionally known batch type equipment,
A multi-can continuous process or the like can be applied, but the continuous process is preferable from the viewpoint of productivity. A conventionally known polycondensation catalyst is used for producing the copolyester. Generally, metal compounds such as titanium, antimony, germanium, tin, cobalt, manganese and zinc are used. Above all, it is preferable to use a titanium compound, an antimony compound or a germanium compound, and among these, it is preferable to use titanium tetrabutoxide, antimony trioxide, germanium dioxide or cobalt acetate. These polycondensation catalysts may be used alone or in combination of two or more.

[0032]

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 parts in the examples mean parts by weight unless otherwise specified.

First, various measuring methods used in the examples will be described. 1. Intrinsic viscosity (IV) 0.1 g of a sample was precisely weighed and dissolved in 25 ml of a mixed solvent of phenol / tetrachloroethane = 3/2 (weight ratio),
It measured at 30 degreeC with the Ostwald viscometer. A suitable IV of the copolyester of the present invention is 0.4 to 1.0 dl /
It is g. If IV is less than 0.4 dl / g, the mechanical strength of the molded product obtained from the copolyester tends to be poor, and conversely, if IV exceeds 1.0 dl / g, the melt viscosity becomes too high and the apparatus It tends to be difficult to manufacture from a physical viewpoint. Desirable IV is 0.45-0.95 dl /
g, more preferably IV is 0.5 to 0.9 dl / g.

2. Calorific value (TC) 10 mg of a sample was sealed in an aluminum pan, heated to 290 ° C. at a heating rate of 20 ° C./min in a nitrogen gas atmosphere, held at the same temperature for 3 minutes, and then the sample pan was rapidly cooled with liquid nitrogen. . Then, the rapidly cooled sample pan was set again, and the calorific value of the exothermic peak generated when the temperature was raised at a temperature rising rate of 20 ° C./min was taken as the calorific value. Shimadzu Corporation D for TC measurement
SE-50 was used and TA60WS manufactured by the same company was used for data analysis.

Since TC is an index showing crystallinity, the smaller the value, the more advantageous from the viewpoint of transparency which is a characteristic of the copolyester of the present invention. Desirable TC is 10 J / g or less, more desirable TC
Is 8 J / g or less. When TC exceeds 10 J / g, it tends to crystallize and the transparency of the copolyester tends to deteriorate. The tendency of deterioration of transparency is not preferable because it becomes remarkable as the thickness of the molded body increases.

3. Evaluation of foreign matter 2 g of the copolyester sample was dissolved in 100 ml of a mixed solvent of phenol / tetrachloroethane = 3/2 (weight ratio), and this was dissolved in Teflon (registered trademark) having a pore diameter of 0.1 μm.
It was filtered with a membrane filter manufactured by. After thoroughly drying the membrane filter, use a scanning electron microscope (SE
M) -An energy dispersive X-ray analyzer was used to perform elemental analysis on foreign substances observed on the filter surface. An S-2500 scanning electron microscope manufactured by Hitachi Ltd. and an EMAX-3000 energy dispersive X-ray analyzer manufactured by Horiba Ltd. were used. The main foreign matter was magnesium carboxylate or phosphate.

The amount of foreign matter contained in the sample of copolyester was determined to be 4 from none, minute, small, and large by observation with SEM.
Graded. Nothing is most preferable, but a minute amount is at a practical level. SEM observation conditions of Comparative Example 4 shown in FIG.
Under the same conditions (1,000 times), none: no particles based on the added metal are observed. Minute: Several particles based on the added metal are observed. Minor: About several tens of particles based on the added metal are observed. Many: Many particles based on the added metal are observed.

4. Melt resistivity value (Si) Two electrode plates were placed in a copolyester melted at 275 ° C., and a current value (i) when a voltage of 120 V was applied
o) was measured and the specific resistance value Si was calculated by the following equation. Si (Ω · cm) = (A / I) × (V / io) where A: electrode area (cm ² ), I: inter-electrode distance (c
m), V: voltage (V).

Since Si is an index relating to electrostatic adhesion, the casting speed at the time of film formation differs depending on the magnitude of this value, and the productivity is affected. A desirable Si value is 0.7 × 10 ⁸ Ω · cm or less, and a more desirable Si value is 0.6 × 10 ⁸ Ω · cm or less. When the Si value exceeds 0.7 × 10 ⁸ Ω · cm, the electrostatic adhesion is significantly deteriorated, the casting speed is reduced, and the productivity is greatly reduced.

5. Casting speed An electrode made of tungsten wire is provided between the die of the extruder and the cooling drum, a voltage of 10 to 15 kV is applied between the electrode and the casting drum, and melt extrusion is performed at 290 ° C. to obtain a film raw material having a thickness of 100 μm. Got the counter. The surface of this raw material film is observed with the naked eye, and the point at which pinner bubbles start to occur is the casting speed (m / min)
And The casting speed is preferably as high as possible in terms of productivity.

6. From haze copolyester, M-15 manufactured by Meiki Seisakusho Co., Ltd.
Using a 0C-DM injection molding machine, a stepped molding plate having a thickness of 2 to 11 mm was molded under the conditions of 290 ° C and a mold temperature of 15 ° C. A haze meter (manufactured by Nippon Denshoku Co., Ltd., Model NDH200) was used for a portion of the stepped molded plate having a thickness of 5 mm.
Haze (%) was measured at 0).

7. Elemental analysis Elemental analysis was performed by the method described below to quantify the amount of each element in the copolyester sample. (1) An analytical sample of Na was ash decomposed with a platinum crucible, 6 mol / L hydrochloric acid was added, and the sample was evaporated to dryness. Dissolve with 1.2 mol / L hydrochloric acid,
It quantified by atomic absorption (Shimadzu, AA-640-12).

(2) An analysis sample of Mg was ash decomposed with a platinum crucible, 6 mol / L hydrochloric acid was added, and the mixture was evaporated to dryness. Dissolve with 1.2 mol / L hydrochloric acid,
ICP emission analysis (Shimadzu Corporation, ICPS-2000)
Was quantified by.

(3) Whether the analytical sample of P is subjected to dry ash decomposition in the presence of sodium carbonate,
Wet decomposition was carried out in a sulfuric acid / nitric acid / perchloric acid system or a sulfuric acid / hydrogen peroxide solution system to convert phosphorus into orthophosphoric acid. Then 1m
In ol / L sulfuric acid solution, molybdate was reacted to form phosphomolybdic acid, and the absorption at 830 nm of heteropoly blue produced by reducing this with hydrazine sulfate was measured with an absorptiometer (UV-150-02, manufactured by Shimadzu Corporation). It was measured and colorimetrically determined.

(4) 2 g of an analysis sample of Ge was ash decomposed in a platinum crucible, 5 ml of 10% sodium hydrogen carbonate solution was added and evaporated, and hydrochloric acid was further added to evaporate to dryness. 400 ° C to 950 ° C in an electric furnace
The temperature was raised to, and left for 30 minutes to melt. 10 ml of water
It was dissolved in the solution with heating and transferred to a germanium distillation apparatus (washing with water 7.5 ml × 2). 35 ml of hydrochloric acid was added and distilled to obtain 25 ml of distillate. An appropriate amount was taken out of the solution, and hydrochloric acid was added so that the final concentration was 1 to 1.5 mol / L.
0.25% polyvinyl alcohol solution 2.5 ml, 1%
Cetyltrimethylammonium chloride solution 2.5m
1 and 0.04% phenylfluorone (2,3,7-trihydroxy-9-phenyl-6-fluorone) solution 5
ml was added and made up to 25 ml with water. A yellow complex with Ge was formed, and the absorbance at 505 nm was measured with an absorptiometer (UV-150-02, manufactured by Shimadzu Corporation) for colorimetric determination.

(5) An Sb analysis sample is wet-decomposed in a sulfuric acid / hydrogen peroxide water system, sodium nitrite is added to give Sb ^5+, and brilliant green is added to form a blue complex with Sb. Extraction with a 625 nm absorptiometer (Shimadzu U, U
V-150-02) for colorimetric determination.

(6) A Ti analysis sample is ash decomposed in a platinum crucible, sulfuric acid and potassium hydrogen sulfate are added, and the mixture is heated and melted. After dissolving in 2 mol / L sulfuric acid, hydrogen peroxide solution was added to form a yellow complex, and the absorbance at 420 nm was measured by an absorptiometer (manufactured by Shimadzu Corporation,
UV-150-02) for colorimetric determination.

(7) Analysis of Co It carried out according to the analysis of Mg.

[Example 1] 570 in an esterification reaction kettle
36 parts terephthalic acid (TPA), 35801 parts ethylene glycol (EG) and 15843 parts 1,4-cyclohexanedimethanol (CHDM) were charged, and
The pressure was adjusted to 25 MPa, and the esterification reaction was performed at a reaction temperature of 220 ° C. to 240 ° C. for 120 minutes. Next, the pressure in the reaction kettle is set to normal pressure, and magnesium acetate tetrahydrate 13
2.39 parts, sodium acetate 5.35 parts, cobalt acetate tetrahydrate 6.34 parts, trimethyl phosphate 61.5
Parts and 8 parts of titanium tetrabutoxide were added, the mixture was stirred for 10 minutes, the reaction system was gradually depressurized, and the reaction mixture was adjusted to 0.
It was set to 5 hPa. During this period, the reaction temperature was raised to 280 ° C. The polymerization reaction was continued for 40 minutes at the same temperature until the melt viscosity reached 7,000 dPa, and then discharged into water in a strand form to obtain the copolyester of Example 1.

The above-mentioned respective measurements were carried out on the obtained copolyester. In the copolyester, Mg was 200 ppm and P was 67% of the added amount, and 116 pp was left.
m was included. Therefore, the Mg / P atomic number ratio is 2.19.
Met. The measurement results are shown in Table 1.

[Examples 2-5, 7, 8 and Comparative Examples 1-
10] Except that the composition of the copolyester was changed as shown in Table 1 and the addition amount of sodium acetate, the addition amount of magnesium acetate, the type and addition amount of the phosphorus compound, and the type and addition amount of the catalyst were changed. Polymerization was performed in the same manner as in Example 1 to obtain respective copolyesters. The measurement results are shown in Table 1.

Example 6 In an esterification reaction kettle, 591
09 parts of dimethyl terephthalate (DMT), 2853
4 parts of 1,4-cyclohexanedimethanol (CHD
M), 16338 parts of ethylene glycol (EG) and 16 parts of titanium tetrabutoxide were charged, and while the methanol produced by the reaction was distilled off, the temperature was raised from 125 ° C to 240 ° C over 120 minutes to carry out the transesterification reaction. Finished. At this point 2.675 parts sodium acetate, 120.65 parts magnesium acetate tetrahydrate,
After adding 7.93 parts of cobalt acetate.tetrahydrate and 79.3 parts of triethyl phosphate, polymerization was carried out in the same manner as in Example 1 to obtain a copolyester. The measurement results are shown in Table 1.

[0053]

[Table 1]

In Table 1, TPA: terephthalic acid, I
PA: isophthalic acid, DMT: dimethyl terephthalate, CHDM: 1,4-cyclohexanedimethanol,
EG: ethylene glycol, Na-OAc: sodium acetate, Mg-OAc: magnesium acetate.tetrahydrate, T
i: titanium tetrabutoxide, Sb: antimony trioxide, Ge: germanium dioxide, Co: cobalt acetate tetrahydrate, TMPA: trimethyl phosphate, TEP
A: Represents triethyl phosphate, respectively.

Regarding the evaluation of foreign matters, a SEM photograph (× 500 times) of Example 4 is shown in FIG. 1 as a representative example, and an elemental analysis chart is shown in FIG. In addition, the SEM photograph of Comparative Example 4 (× 1,00
3 is shown in FIG. 3 and the elemental analysis chart is shown in FIG. The sample of Example 4 has no foreign matter based on metal,
In Comparative Example 4, a large amount of foreign substances due to magnesium and phosphorus are present. These foreign matters have a large adverse effect, such as causing filter clogging during molding and processing, and causing a fish eye in films and sheets.

From Table 1, all of the copolyesters of Examples 1 to 8 have no or very little foreign matter, have a small haze value and excellent transparency, and have a small melt specific resistance value and excellent electrostatic adhesion. Was there. Therefore, it was found that a high casting speed was obtained and the productivity was excellent.

On the other hand, in Comparative Example 1, magnesium acetate
Since the tetrahydrate and the phosphorus compound were not added, the melt specific resistance was large and the electrostatic adhesion was poor. Since Comparative Example 2 has a low sodium content, Comparative Examples 3, 5 and 6 have M ²
Since the / P ratio was small, the melt resistivity was large and the electrostatic adhesion was poor. In Comparative Example 4, since the M ² / P ratio is large,
There were many foreign substances and the transparency was very poor. In Comparative Examples 7 and 8, the copolymerization ratio of CHDM was out of the range of the present invention, crystallization was likely to occur, and transparency was very poor. Comparative Example 9
Since the content of sodium was high, there were many foreign substances and the transparency was very poor. In Comparative Example 10, since no phosphorus compound was added, the amount of foreign matter was large and the transparency was very poor, and the melt resistivity was large and the electrostatic adhesion was also poor.

[0058]

According to the present invention, 1,4-cyclohexanedimethanol, which is a glycol component constituting a copolyester, has a specific copolymerization ratio and contains a specific amount of an alkali metal compound, and an alkaline earth metal. By containing the compound and the phosphorus compound in a specific ratio, a copolyester having few foreign matters and excellent transparency and electrostatic adhesion is provided.

The copolymerized polyester of the present invention can be used not only as a film, a sheet, a decorative board, a building material, etc., but also as a blending component with other polymers such as PET to improve the transparency of other polymers. And mechanical properties can be improved.

[Brief description of drawings]

FIG. 1 is a SEM photograph of Example 4.

FIG. 2 is an elemental analysis chart of Example 4.

FIG. 3 is an SEM photograph of Comparative Example 4.

FIG. 4 is an elemental analysis chart of Comparative Example 4.

Continued front page    (72) Hideki Shimizu, inventor             Toyobo Co., Ltd. 10-24 Toyocho, Tsuruga City, Fukui Prefecture             Expression company Polymer Development Center F-term (reference) 4J002 CF051 DE056 DE067 DE226                       DH028 DH038 EC076 EG026                       EG037 EW128 FD206 FD207                       FD208 GG01 GG02 GK00                       GL00 GL01 GT00                 4J029 AA03 AB01 AB07 AC02 AD10                       AE01 AE02 AE03 BA03 BA04                       BA05 BD07A CA02 CA06                       CB05A CB06A CB10A CC06A                       CD03 JA093 JA123 JA233                       JB133 JB173 JC413 JF013                       JF113 KA02 KB02 KB04

Claims (3)

[Claims] 1. A copolyester composed of one or a plurality of acid components and a plurality of glycol components, wherein one of the glycol components is 1,4-cyclohexanedimethanol (CHDM), The copolymerization ratio of 1,4-cyclohexanedimethanol to all glycol components is in the range of 20 to 80 mol%, the alkali metal compound is contained in an amount of metal atom (M ¹ ) of 5 ≦ M ¹ ≦ 100 ppm, and the alkali As the atomic number ratio (M ² / P) of the metal atom (M ² ) of the alkaline earth metal compound and the phosphorus atom (P) of the phosphorus compound, the earth metal compound and the phosphorus compound are 1.2 ≦ M ² / A copolyester which is contained so that P ≦ 5. 2. The copolyester according to claim 1, wherein the main acid component is terephthalic acid, and the glycol component contains ethylene glycol. 3. The alkaline earth metal compound is a metal atom (M
^The copolymerized polyester according to claim 1 or 2, wherein the content of ² ) is 40 ≦ M ² ≦ 400 ppm.