JP2636436B2 - Method for producing polyester composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a vent-type molding machine having an average particle size of 0.01 to 5 particles.
The present invention relates to a method for producing a polyester containing inorganic particles of μm.

[Prior art] Polyester, especially polyethylene terephthalate,
Due to its excellent physical and chemical properties, it is widely used as fibers, films and other molded products. However, contrary to its excellent properties, undesired troubles such as deterioration in workability due to poor processability in the molding process for obtaining the above molded product, poor slipperiness in handling the product itself, and reduction in product value occur. Is also known.

To solve these problems, a number of methods have been proposed to improve the slipperiness of the surface of the molded product by adding fine particles in the polyester and imparting appropriate irregularities to the surface of the molded product, some of which have been put to practical use. ing. For example, there is a method in which inert inorganic particles such as silicon oxide, titanium dioxide, calcium carbonate, talc and kaolinite are added to polyester (for example, JP-A-55-133431).

However, the method of adding these inert inorganic particles,
Often, coarse particles are mixed. When such coarse particles are present, for example, in a magnetic tape film,
The film deteriorates the electromagnetic conversion characteristics, causes a dropout, and, in the case of a film requiring transparency such as plate making, for a microfilm, etc., impairs the film quality such that the transparency is significantly reduced. .

As a method for removing such coarse particles, generally, when adding at the time of a polyester synthesis reaction, it is added in a slurry state or a solution state by performing pulverization, classification operation and the like. In addition, when kneading and compounding with polyester, the powdery particles are dispersed in the polymer by a method such as applying a strong shear stress to the polymer and the particles for a long time using a single-screw or twin-screw extruder. I have.

However, in the former case, crushing and classification operations require a great deal of cost and work time, and even if this operation is performed, the incorporation of coarse particles cannot be avoided. In addition, in the case of producing a variety of added-value polymers from a kind of base polymer in recent years, if it is added during the polymerization reaction, a large amount of loss is caused by switching the brand.

On the other hand, the latter involves adding and kneading powdery particles to the polymer, so that the incorporation of coarse particles cannot be avoided.If a strong shearing stress is applied for a long time to further improve the dispersibility, the intrinsic viscosity of the polymer decreases significantly. As a result, the moldability or product quality deteriorates.

Therefore, the present inventors have intensively studied to improve the drawbacks of the above-described conventionally used particle addition method, and particularly to obtain a polyester film excellent in lubricity and uniformity of the film surface, abrasion resistance and the like. As a result, the present invention has been achieved.

[Problems to be Solved by the Invention] An object of the present invention is to make it possible to easily add inorganic particles to polyester, to reduce the intrinsic viscosity of the obtained polymer little, and to have good dispersibility of the inorganic particles. For,
An object of the present invention is to obtain a polyester excellent in lubricity, surface uniformity and abrasion resistance, which cannot be achieved by the prior art.

[Means for Solving the Problems] The object of the present invention described above is to produce a polyester containing inorganic particles, in a vent-type molding machine, water and / or boiling point of the inorganic particles having an average particle size of 0.01 to 5 µm in the polyester. This can be achieved by a method for producing a polyester composition, which comprises adding an organic compound slurry at a temperature of 200 ° C. or lower.

The bifunctional acid component of the polyester of the present invention is mainly composed of an aromatic dicarboxylic acid or an ester-forming derivative thereof, and specifically includes terephthalic acid, 2,6-naphthalene dicarboxylic acid, and 1,2-bis (Chlorophenoxy) ethane-4,4-dicarboxylic acid, its ester-forming derivatives dimethyl terephthalate, dimethyl 2,6-naphthalenedicarboxylate, dimethyl 1,2-bis (chlorophenoxy) ethane-4,4-dicarboxylate Among them, terephthalic acid or dimethyl terephthalate is preferable. Examples of the glycol component include ethylene glycol, butylene glycol, diethylene glycol, propylene glycol, polyethylene glycol, and 1,4-cyclohexanedimethanol. Of these, ethylene glycol is preferable. In addition to these dicarboxylic acids or their ester-forming derivatives and glycol components, other components may be copolymerized, such as diethylene glycol, propylene glycol, neopentyl glycol, polyalkylene glycol, p-xylylene glycol, 1 Diol components such as 1,4-cyclohexanedimethanol and 5-sodium sulforesorcin; dicarboxylic acid components such as adipic acid, sebacic acid, phthalic acid, isophthalic acid, 2,6-naphthalene dicarboxylic acid, and 5-sodium sulfoisophthalic acid; Multifunctional dicarboxylic acid components such as melitic acid and pyromellitic acid,
Oxycarboxylic acid components such as p-oxyethoxybenzoic acid and the like can be mentioned.

When the dicarboxylic acid component is a dicarboxylic acid, it is subjected to an esterification reaction with glycol, and when the dicarboxylic acid ester is a dicarboxylic acid ester, after a transesterification reaction with glycol, polycondensation is carried out at a high temperature under reduced pressure to obtain a polyester.

It is also possible to carry out polycondensation using the prepolymer itself as a starting material. As the polyester obtained from such a monomer, polyethylene terephthalate and polyethylene-2,6-naphthalate are preferred, and polyethylene-2,6-naphthalate is particularly preferred for applications requiring high rigidity.

As the inorganic particles used in the present invention, specifically,
For example, colloidal silica, wet silica, silicon oxide such as dry silica, titanium oxide, calcium carbonate, α-, β
-, Γ, δ-alumina, talc, kaolinite and the like. Among them, colloidal silica, titanium oxide and calcium carbonate are preferred.

In the present invention, the average particle size of the inorganic particles dispersed and contained in the polyester needs to be 0.01 to 5 μm, and more preferably 0.05 to 2 μm. Average particle size is 0.01μm
If the amount is less than the above, when the film is formed, the slipperiness decreases. When the average particle size exceeds 5 μm, the wear resistance is increased due to the coarse protrusions,
Electromagnetic conversion characteristics become poor.

The amount of the inorganic particles added to the polyester is preferably 0.0001 to 50% by weight, more preferably 0.001 to 50% by weight.
-20% by weight, more preferably 0.01-10% by weight.

In the present invention, when obtaining an inorganic particle-containing polymer in which inorganic particles are uniformly dispersed in a polymer, the water and / or boiling point of the inorganic particles are added to the polyester in a vent-type molding machine.
Add an organic compound slurry of 0 ° C or less, remove water and / or organic compounds having a boiling point of 200 ° C or less under heating and reduced pressure,
It is obtained by melt-kneading. The vent molding machine is a melt molding machine provided with at least one vent hole, and may be, for example, an extrusion molding machine or an injection molding machine. At least one of the vent holes for removing water and / or organic compounds having a boiling point of 200 ° C. or lower must be kept under reduced pressure. Further, the degree of pressure reduction of the vent hole is preferably maintained at 100 Torr or less, more preferably 50 Torr or less, and 30 Torr or less.
The following are more preferred. By setting the degree of depressurization of the vent hole to a specific range in this manner, the reduction of the intrinsic viscosity of the polyester can be reduced to 0.05 or even 0.02 even when directly using undried pellets, particularly a high moisture content pellet having a moisture content of 0.2% by weight or more. Since it can be suppressed to a low level, a significant cost reduction in the manufacturing process can be achieved.

On the other hand, it is necessary to add the inorganic particles to the polyester as water and / or an organic compound slurry having a boiling point of 200 ° C. or lower. Examples of the organic compound having a boiling point of 200 ° C. or lower include alcohols such as methanol, ethanol, and ethylene glycol, hydrocarbon compounds such as benzene and toluene, and esters, ketones, and amines, but are not particularly limited. . Among them, water is preferred from the viewpoint of handling properties, removability and the like. Of course, water and / or the organic compound may be a mixed solvent of two or more kinds, and in that case, a water-rich mixed solvent is preferable.

Furthermore, the concentration of water and / or the organic compound slurry having a boiling point of 200 ° C. or less of the inorganic particles is not particularly limited, but the amount of water and / or the organic compound having a boiling point of 200 ° C. or less to the polymer is preferably 2% by weight or more and 30% by weight or less. preferable. More preferably, the content is 2% by weight or more and 20% by weight or less. 2% by weight
If it is less than 1, the dispersibility in the polymer tends to deteriorate, which is not preferable. If it exceeds 30% by weight, the intrinsic viscosity of the polymer tends to decrease, which is not preferable.

By using the method of the present invention, a high concentration of inorganic particles can be contained in the polyester. Therefore, a polyester containing a high concentration of inorganic particles can be produced and diluted with a substantially particle-free polyester for use.

Also in the present invention, the inorganic particles are added to the polyester in the form of water and / or an organic compound slurry having a boiling point of 200 ° C. or less,
Mixing is possible, and the intrinsic viscosity of the obtained polymer is less reduced.

Further, the inorganic particles in the obtained polymer are uniformly dispersed. Therefore, when the film is formed into a stretched film, a uniform uneven surface is obtained, and a film having both slipperiness and abrasion resistance is obtained.

Further, the polyester of the present invention contains a metal compound catalyst of a compound such as lithium, sodium, calcium, magnesium, manganese, zinc, antimony, germanium, titanium or the like usually used in the production of the polyester, a phosphorus compound as a coloring inhibitor, and the like. You may go out.

[Example] Hereinafter, the present invention will be described in detail with reference to examples. In addition, each characteristic value measurement of the obtained polyester was performed according to the following method.

(A) Particle size of particles The average particle size was measured by an electron micrograph of the particles.
It was determined by the particle equivalent sphere diameter corresponding to the volume% point. The equivalent sphere diameter is the diameter of a sphere having the same volume as a particle.

(B) Intrinsic viscosity of polymer Measured at 25 ° C using o-chlorophenol as a solvent.

(C) Dispersion state of particles in polymer After the polymer was cut into an ultrathin section of about 0.3 μm by an ultrathin film forming apparatus, the dispersion state of particles in the polymer was observed by a transmission electron microscope.

 The state of dispersion was determined as follows.

：: The secondary aggregated particles were hardly observed and the object was achieved.

Δ: Secondary aggregated particles were slightly present, and the purpose was not achieved.

X: The objective is not achieved because most of the particles are secondary aggregated particles.

(D) Film characteristics (1) Surface roughness Ra (μm) Measured using a stylus type surface roughness meter according to JIS-B-0601 (cutoff value 0.08 mm, measurement length 4 mm).

(2) Slippery (μk) Slit the film to 1/2 inch and use a tape running tester TBT-300 (Yokohama System Laboratory Co., Ltd.) to run at 20 ° C and 60% RH atmosphere. Then, the initial μk was determined by the following equation.

μk = 0.733 log (T ₁ / T ₂ ) where T ₂ is the incoming tension and T ₁ is the outgoing tension. The guide diameter is 6mmφ, the guide material is SUS27 (surface roughness 0.2S),
The winding angle is 180 ° and the running speed is 3.3cm / sec.

Those having the above μk of 0.35 or less have good slipperiness.
Here, μk is 0.35, which is a critical value as to whether or not the slipperiness when processing a film or as a product is extremely deteriorated.

(3) Wear resistance Using a tape running tester TBT-300 (manufactured by Yokohama System Laboratory Co., Ltd.), the tape was repeatedly run 1000 times in an atmosphere of 25 ° C. and 50 RH. The shaved powder (white powder) is visually determined.

Here, the guide diameter is 8mmφ, and the guide material is SUS27
(Surface roughness 0.2S), winding angle 180 °, tape running speed 3.3cm / sec. The evaluation criteria are as follows.

A: The amount of white powder generated is very small, and the object is achieved.

：: The amount of white powder generated is small, and the object is achieved.

Δ: The amount of white powder generated was rather large, and the purpose was not achieved.

X: The amount of white powder generated is extremely large, and the object is not achieved.

Example 1 An undried polyethylene terephthalate chip having an intrinsic viscosity of 0.615 containing 0.4% by weight of water was melted using a vent type twin screw extruder, and the content in the final polymer was reduced to 5% by weight. Average particle size
A 0.3 μm aqueous slurry of colloidal silica particles (7.5% by weight based on polymer) was added. The vent port was maintained at a vacuum of 10 Torr, and the mixture was melt-extruded at a resin temperature of 280 ° C. to obtain polyethylene terephthalate containing colloidal silica particles. The intrinsic viscosity of the obtained polymer was 0.605, and a polymer in which the intrinsic viscosity was significantly reduced was obtained. As a result of observing the polymer with a transmission electron microscope, it was found that the polymer was almost in a monodispersed state.

The obtained polymer was adjusted using a polymer containing no particles so that the colloidal silica particles contained 0.5% by weight of the colloidal silica particles. The polymer was melt-extruded at 290 ° C., and the surface temperature was adjusted using an electrostatic application casting method. It was wound around a casting drum at 30 ° C. and solidified by cooling to obtain an unstretched film having a thickness of about 150 μm. This unstretched film was stretched 3.4 times in the machine direction at 90 ° C. and 3.6 times in the transverse direction at 100 ° C. Then 2
It was heat-set at 10 ° C. to obtain a 15 μm thick biaxially stretched film. As a result of evaluating the film properties, flatness, slipperiness,
The abrasion resistance was good (Table 1).

Examples 2 to 5, Comparative Example 1 Polyethylene terephthalate was obtained using a vented extruder in the same manner as in Example 1 except that the particle composition and the average particle diameter of the contained inorganic particles were changed. The particles dispersed in the polymer had little secondary agglomeration and were almost monodispersed. The polymer was made into a biaxially oriented film in the same manner as in Example 1. When a film having a particle composition and an average particle diameter of the inorganic particles contained within the range of the present invention was formed into a film, the film had excellent flatness, slipperiness, and abrasion resistance (Examples 2 to 5).

However, when the average particle size of the inorganic particles was outside the scope of the present invention, when the film was formed, it was not possible to satisfy all of the flatness, the slipperiness, and the abrasion resistance (Comparative Example 1).

Comparative Example 2 A transesterification reaction was carried out from 100 parts by weight of dimethyl terephthalate and 70 parts by weight of ethylene glycol using 0.09 parts by weight of calcium acetate as a catalyst in a conventional manner. To the product were added 0.03 part by weight of antimony trioxide, 0.3 part by weight of trimethyl phosphate, and 5 parts by weight of an ethylene glycol slurry of calcium carbonate particles having an average particle size of 0.5 μm as particles.

Most of the particles in the polymer were secondary aggregated, and the dispersibility was poor. The polymer was made into a biaxially oriented film in the same manner as in Example 1. The surface of the obtained film had many coarse projections, and it was not possible to satisfy both the slipperiness and the abrasion resistance.

Comparative Example 3 Polyethylene terephthalate having an intrinsic viscosity of 0.620 was dried at a temperature of 180 ° C. under reduced pressure. The chip and average particle size 0.3μm
The titanium oxide powder was blended at 5% by weight using an extruder to obtain titanium oxide-containing polyethylene terephthalate. The dispersion state of the particles in the polymer was very poor, and most of the particles were aggregated. The obtained polymer was made into a biaxially oriented film in the same manner as in Example 1. The surface of the obtained film had many coarse particles and could not satisfy both the slipperiness and the abrasion resistance.

[Effects of the Invention] The following excellent effects are exhibited by using the polyester production method of the present invention.

(1) Inorganic particles can be added to and mixed with polyester in the form of slurry of water and / or an organic compound having a boiling point of 200 ° C. or less, and a uniformly dispersed polyester containing inorganic particles can be easily obtained. Therefore, in the case of forming a film, there is no clogging of the filter during the melt molding process, and there is no breakage of the filter film due to coarse particles.

(2) Since the inorganic particles are uniformly dispersed in the polyester, when formed into a stretched film, a uniform uneven surface is obtained, and the film has excellent slipperiness and abrasion resistance. Such a film is suitable for magnetic tape applications, photography, plate making applications, condenser applications, and the like.

 ────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-59-100156 (JP, A) JP-A-60-35020 (JP, A) JP-A-60-217235 (JP, A) JP-A-62 131016 (JP, A) JP-A-61-168654 (JP, A)

Claims (6)

(57) [Claims] In producing a polyester containing inorganic particles, a vent-type molding machine is used to add water and / or a boiling point of inorganic particles having an average particle size of 0.01 to 5 μm to the polyester.
A method for producing a polyester composition, comprising adding an organic compound slurry at 0 ° C. or lower. 2. The amount of the inorganic particles added to the polyester is
The method for producing a polyester composition according to claim 1, wherein the amount is 0.0001 to 50% by weight. 3. The process for producing a polyester composition according to claim 1, wherein the amount of water and / or organic compound added to the polyester is 2 to 30% by weight. 4. The method for producing a polyester composition according to claim 1, wherein the degree of pressure reduction of at least one vent hole of the vent-type molding machine is 100 Torr or less. 5. The method for producing a polyester composition according to claim 1, wherein the intrinsic viscosity of the polyester is reduced by 0.05 or less. 6. The method according to claim 1, wherein the inorganic particles are at least one selected from the group consisting of silicon oxide, titanium oxide, calcium carbonate, alumina, talc, and kaolinite. 2. A method for producing the polyester composition according to item 1.