JP3121449B2 - Polyester-based manufacturing method - Google Patents

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 polyester base containing polyethylene terephthalate as a main constituent unit containing silica particles containing silica particles having uniform, less coarse particles, smoothness, good transparency and improved slipperiness. .

[0002]

2. Description of the Related Art Polyesters, particularly polyesters containing polyethylene terephthalate (hereinafter referred to as PET) as a main component, are widely used as molding materials for fibers, films, sheets and the like because of their excellent properties.

[0003]

However, since the base or sheet of the polyester lacks slipperiness as it is, it has been proposed to mix various powders at the time of producing polyester chips or at the time of film formation. It is not always satisfactory, for example, generation of coarse particles due to aggregation of bodies, and a film having poor surface properties due to poor electrostatic application properties. The present invention provides a method for producing a polyester base that is transparent, has good slipperiness, and has excellent electrostatic application properties during film formation.

[0004]

The present invention relates to a process for producing a polyester from terephthalic acid, which is a main dicarboxylic acid, and ethylene glycol, which is a main alkylene glycol, during the esterification reaction. An ethylene glycol-soluble compound containing an atom selected from the above is added, and at the stage when the esterification reaction is substantially completed, (b) phosphoric acid or phosphorous acid or an ester compound thereof and (c) a compound represented by the following general formula (1) (D) between the time before the esterification reaction and the start of the polycondensation reaction, and (d) continuous or intermittent use of fine particle silica having a particle size of 0.1 μm to 4 μm as an ethylene glycol slurry. And forming the resulting polyester into a film. General formula (1)

[0005]

Embedded image

Here, R ₁ and R ₂ are an alkyl group having 1 to 8 carbon atoms or an aromatic residue, which may be the same or different. More particularly, the silica particles in the polyester base obtained according to the present invention have an average particle size of 0.8 μm.
m and a particle size of 1 to 4 μm (particle A) and a particle size of 0.1 to 1
μm (particle B) is distributed in the ratio of the following general formula (2), and the content of silica in the polyester base is (particle A)
And (particle B) are preferably 0.001 to 1.0% by weight, preferably 0.005 to 1.0% by weight. General formula (2) 1/4 ≦ (particle A) / (particle B) ≦ 3/5

[0007] The ethylene glycol-soluble compound containing an atom selected from Mg, Mn and Zn and phosphoric acid or phosphorous acid or an ester compound thereof are substantially present in the polyester in an amount of 2.5 ≦ M / P ≦ 6 (where M represents a metal element of a compound containing an atom selected from Mg, Mn and Zn, P represents a P element of phosphoric acid or phosphorous acid or an ester compound of these compounds, And M is 20 to 150 ppm, preferably 40 to 120 ppm, and more preferably 5 to 100 ppm of an imidazole compound represented by the general formula (1). According to the present invention, it is possible to obtain a polyester and a polyester base having excellent transparency, good slipperiness, and excellent electrostatic applicability.

For the polyester-based film formation, it is possible to form a film using only silica-containing pellets, but it is also possible to use a so-called master batch method. That is, the desired silica-containing base can be obtained by mixing silica-containing pellets and pellets containing no silica and forming a film.

The polyester referred to in the present invention comprises terephthalic acid (hereinafter referred to as PTA) and ethylene glycol (hereinafter referred to as E).
G) is a main component of PET obtained by polycondensation, but may contain other copolymer components as long as the properties of PET are not impaired. That is, for example, dicarboxylic acids such as isophthalic acid, phthalic acid, sodium sulfoisophthalic acid, aromatic dicarboxylic acids such as naphthalenedicarboxylic acid, adipic acid, sebacic acid, aliphatic dicarboxylic acids such as azelaic acid, and cyclohexanedicarboxylic acid. Alicyclic dicarboxylic acids and the like. Similarly, glycols such as propylene glycol, diethylene glycol, aliphatic glycols such as butanediol,
Alicyclic or aromatic glycols such as cyclohexanedimethanol and xylylene glycol can be mentioned. If necessary, an antioxidant, an antistatic agent, an ultraviolet inhibitor, and a coloring agent (dye, etc.) can be added.

The silica particles referred to in the present invention include silica (particle A) having an average particle diameter of 0.8 μm and a particle diameter of 1/4 μm and silica (particle B) having a particle diameter of 0.1 to 1 μm. Particles distributed in the ratio of the general formula (2).
During the ET synthesis, it is added at an arbitrary stage until the polycondensation reaction is started. If the silica particle size is as large as 4 μm or more, the base after film formation becomes a base having a large haze due to voids (voids) generated around the silica particles and a large flatness of projections. Furthermore, in the case of silica having a small particle diameter of 0.1 μ or less, if a particle amount necessary for ensuring the slipperiness of the base is added, the base becomes large in haze and lacks in transparency. It has been found that the presence of the particles A and B in the ratio as shown in the general formula (2) of the present invention makes it possible to obtain a base having excellent transparency and good slipperiness. In order to obtain a PET base containing silica, it is possible to form a film by mixing silica particles with PET pellets at the time of film formation, but a base having good flatness and no haze without agglomerated coarse particles is required. In order to obtain it, it is most preferable to add and mix the EG slurry to the reaction system at an arbitrary stage during the synthesis of PET, particularly before the start of the polycondensation reaction.

The turbidity (haze) and other characteristics of the base
CaCO within the range that does not impair_Three, TiO_Two, Al _TwoO_ThreePowder like
It can also be added. These additives are PET
It can be added during synthesis, but must be mixed with pellets during film formation.
Can also be. The imidazo represented by the general formula (1) of the present invention
Compounds and atoms selected from Mg, Mn and Zn compounds
The coexistence of metal compounds containing
Since pellets with excellent chargeability can be obtained,
A film can be formed and adhesion with the cooling roll is improved.
Therefore, a base having good flatness can be obtained.

The synthesis and film formation of the PET of the present invention can be carried out by a usual method, which will be described below with reference to an example.
The synthesis of PET may be a batch system or a continuous system, and may be a transesterification system or a direct esterification system. Here, an example of a batch direct esterification system will be described. Stirrer, rectification column, the esterification reaction kettle equipped with N ₂ inlet PT
Charge A and EG, and stir with N ₂ to 1-4 kg / cm.
Press to ² and heat. While extracting the water distilled by the reaction from the rectification column, the temperature of the reaction solution is finally raised to 250 ° C.
Up to The end point of the reaction is determined by the amount of distillate distilled out, and this reaction usually requires 3 to 6 hours. The silica particles are added as an EG slurry at any stage before the start of the polycondensation reaction.

After the completion of the esterification reaction (oligomer) thus obtained, it is transferred to a polycondensation reactor equipped with a stirrer, a distilling tube, an N ₂ introducing tube and a vacuum pipe and heated to 280 ° C. 300 ppm of antimony trioxide is added as a polycondensation reaction catalyst, and the inside of the reaction system is evacuated. The degree of vacuum was gradually increased to 1.0 mmHg. The desired viscosity was reached in about 3.5 hours. The polymer is taken out in a strand form from the bottom of the kettle, cooled in water and then cut into a length of 3 to 5 mm to obtain a pellet. The silica-containing pellets thus obtained are synthesized with a silica-free clear PE
T and the pellets were mixed, dried, and melt-extruded to obtain an amorphous base. This base was stretched 3.5 times in the longitudinal direction and then 3.5 times in the transverse direction, and heat-set to obtain a stretched base having a thickness of 50 μm. The base can also have improved heat shrinkage by annealing at temperatures below Tg.

[0014]

The present invention will be described below with reference to examples. In the examples, “parts” means “parts by weight” unless otherwise specified. In the present invention, particle size distribution, transparency (haze),
The surface properties, the coefficient of friction, and the applicability of static electricity are measured as follows. (Particle particle size distribution) Silica particles were uniformly dispersed in ethylene glycol by ultrasonic treatment, and the particle size distribution of the dispersion was determined using a Horiba ultracentrifugal automatic particle size distribution analyzer (CAPA-700). (Transparency (Haze)) The transparency (haze) of the film base was measured according to ASTM-D1003-52. (Surface properties) The surface properties were measured using a stylus type three-dimensional surface roughness meter (Kosaka Laboratory), needle diameter 2 μm, load 30 mg, cut-off 0.
The center line average roughness (Ra) was measured under the condition of 25 mm. (Friction Coefficient) Two bases were stacked and a constant load was applied to measure the friction coefficient between the base surfaces. At this time, the friction coefficient at the moment when the base started to move was defined as the static friction coefficient, and the friction coefficient at the time when the movement was stabilized was defined as the dynamic friction coefficient. (Electrostatic application property) A thin wire electrode is provided between the die of the extruder and the cooling drum, and a DC voltage of 5 kV is applied between the thin wire and the cooling drum, and a film forming speed of 50 m / min is excellent. It was determined whether the film could be formed (膜) or not (×).

Example 1 17.3 kg of PTA, 8.4 kg of EG and 14.0 g of magnesium acetate tetrahydrate were charged into an esterification reactor and added with N ₂ to 3 kg / cm ² with stirring. Press and heat.
The temperature of the reaction solution was finally raised to 250 ° C. while extracting the distillate produced by the reaction from the rectification column. When the esterification reaction reaches 90% from the amount of distillate, 20% E
200 g of silica particles having an average particle size of 0.8 μm as a G slurry and having a distribution ratio shown in Table 1 were added, and the esterification reaction was continued to complete. The reaction solution was transferred to a polycondensation reactor heated to 280 ° C., and 4.0 g of trimethyl phosphate, 1.0 g of 2-ethyl-4-methylimidazole (hereinafter referred to as EMI) and 6.0 g of trimethyl phosphate were stirred. Add antimony oxide and apply vacuum. The degree of vacuum was gradually increased to 1.2 mmHg. The reaction was terminated when a predetermined melt viscosity was reached. The phenol / tetrachloroethane; IV in a 50/50 mixed solution at 25 ° C. was 0.665. Obtained silica-mixed polymer 40
The mixture was thoroughly mixed with 960 parts of clear PET containing no silica, and dried under vacuum at 140 ° C. for 5 hours. 300 ℃
After being melt-extruded at 95 ° C., stretched in the vertical direction at 95 ° C. and further in the horizontal direction at 100 ° C., and then heat-set to obtain a 50 μm base. Table 1
Table 2 shows the synthetic formula, and Table 2 shows the properties.

Example 2 20 parts of the silica-containing pellet obtained in Example 1 was mixed with 980 parts of clear PET and dried, and a 50 μm base was obtained in the same manner as in Example 1. Table 1 formulas, Table 2
Shows the characteristics.

Example 3 60 parts of the silica-containing pellet obtained in Example 1 was mixed with 900 parts of clear PET and dried, and a 50 μm base was obtained in the same manner as in Example 1. Table 1 formulas, Table 2
Shows the characteristics.

COMPARATIVE EXAMPLE 1 In place of the silica used in Example 1, silica particles having an average particle size of 2.8 μm were used in the same manner as in Example 1 except that the silica particles were 50 μm.
Of Comparative Example 1 was obtained. The formulation is shown in Table 1 and the properties are shown in Table 2, but are inferior in transparency and coefficient of friction as compared with the base of Example 1.

Comparative Example 2 The silica used in Example 1 was used, but a polymer was prepared without using magnesium acetate EMI during the synthesis of the polymer.
Further, a base of Comparative Example 2 having a thickness of 50 μm was obtained. The formulation is shown in Table 1 and the characteristics are shown in Table 2. However, compared with Example 1, the electrostatic applicability at the time of film formation is inferior.

Comparative Example 3 A base of Comparative Example 4 having a thickness of 50 μm was obtained in exactly the same manner as in Example 1 except that no silica particles were used. The formulation is shown in Table 1 and the properties are shown in Table 2, but the friction coefficient is inferior to that of Example 1.

[0021]

[Table 1]

[0022]

[Table 2]

As can be seen from Tables 1 and 2, the polyester base obtained by the present invention has excellent slipperiness, good transparency, and excellent electrostatic applicability during film formation, so that an economical film formation speed can be obtained. it can.

──────────────────────────────────────────────────続 き Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FI C08K 5/51 C08K 5/51 C08L 67/02 C08L 67/02 // B29K 67:00 (56) References JP-A-3-3 292323 (JP, A) JP-A-4-1224 (JP, A) JP-A-3-269016 (JP, A) JP-A-3-234735 (JP, A)

Claims (4)

(57) [Claims] (1) In producing a polyester from terephthalic acid, which is a main dicarboxylic acid, and ethylene glycol, which is a main alkylene glycol, (a) an atom selected from Mg, Mn and Zn during an esterification reaction. The ethylene glycol-soluble compound containing is added, and at the stage when the esterification reaction is substantially completed, (b) phosphoric acid or phosphorous acid or an ester compound thereof and
(c) An imidazole compound represented by the following general formula (1) is added, and between the time before the esterification reaction and the start of the polycondensation reaction, (d) the fine particle silica having a particle size of 0.1 μm to 4 μm is ethylene A method for producing a polyester base, comprising continuously or intermittently adding a glycol slurry to form a film of the obtained polyester. General formula (1) Here, R ₁ and R ₂ are an alkyl group or an aromatic group residue having 1 to 8 carbon atoms, which may be the same or different. 2. The silica particles have an average particle size of 0.8 μm,
And silica (particle A) having a particle diameter of 1 to 4 μm and a particle diameter of 0.1 to
2. A particle in which 1 μm silica (particle B) is distributed in a ratio represented by the following general formula (2), and the content of silica in the polyester base is 0.001 to 1.0% by weight.
The method for producing a polyester base according to the above. General formula (2) 1/4 ≦ (particle A) / (particle B) ≦ 3/5 3. An ethylene glycol-soluble compound containing an atom selected from Mg, Mn and Zn and a phosphoric acid or a phosphorous acid or an ester compound of these compounds are present in the polyester in an amount of 2.5 ≦ M / P
≦ 6 (where M represents a metal element of a compound containing an atom selected from Mg, Mn and Zn, P represents a phosphorus element of phosphoric acid or phosphorous acid or an ester compound thereof, and the numerical value is element / element 2. The process according to claim 1, wherein the imidazole compound represented by the general formula (1) is present in an amount of 20 to 150 ppm, and 5 to 100 ppm. 4. The process for producing a polyester base according to claim 1, wherein the polyester containing silica and the polyester containing no silica are mixed and melt-formed to form a polyester base.