JPS6123623A - Production of polyester - Google Patents

Abstract

PURPOSE:To produce a polyester in which fine particles are finely dispersed and are not agglomerated into coarse particles, by adding a slurry of inorganic fine particles obtained by a specified method to the reaction system for producing the polyester. CONSTITUTION:In the production of a polyester from a dicarboxylic acid component and a glycol, a slurry of fine inorganic particles obtained by mixing with agitation inert fine inorganic particles A (e.g., TiO2 or CaCO3) having an average primary particle diameter <=5mu with particles B (e.g., alumina or glass micro-balloons) having a diameter of 10-4,000 times the average primary particle diameter of fine inorganic particles A and an average particle diameter <=0.5mm. and separating particles B from the mixture is added to a reaction system for producing the polyester. The dispersibility of the inert fine inorganic particles in the slurry can be improved, so that it is possible to produce a polyester which has an extremely low content of agglomerated coarse particles and in which the inorganic fine particles are dispersed as particles of a size as fine as the primary particle diameter.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a method for producing a polyester with few aggregated particles and well dispersed particles.

[Prior art and its problems]

In general, saturated linear polyesters, such as polyethylene terephthalate, have excellent physical and chemical properties and are widely used as fibers, films, and other molded products. However, contrary to its excellent properties, workability deteriorates due to poor slipperiness in the molding process to obtain the above molded product, post-processing processes such as surface treatment, or handling of the product itself. Decrease in value and when unfriendly troubles arise. In order to solve these problems, a method is generally used in which fine particles are incorporated into polyester to impart appropriate irregularities to the surface of the molded product, thereby improving the surface smoothness of the molded product. It is known that inorganic compounds that are insoluble and inactive in polyester, such as titanium dioxide, calumium carbonate, talc, and kaolin, are used as such fine particles. A glycol slurry is prepared and added to the polyester manufacturing process. However, it is well known that these inorganic fine particles generally have poor affinity for glycols and polyesters, and therefore have the disadvantage of agglomerating in slurry or during polyester production. The presence of aggregated coarse particles in the polymer causes yarn breakage during spinning, and also causes problems such as wear of the yarn guide and spinneret. Furthermore, in films, it causes coarse protrusions, wrinkles, and eyes. In particular, when applied to films for magnetic tapes, there is a need for the development of a technology for suppressing the formation of aggregated coarse particles to prevent dropouts (missing memory) and reductions in the S/N ratio.

In order to solve this problem, a dispersant is used when preparing the slurry to improve the dispersibility of the slurry (@ Kaisho 51-6
8695, JP 54-131694, JP 56-88426, etc.) When adding slurry to a polymerization reaction system, a dispersant is added together with the slurry to improve dispersibility in the polymer. Measurement (Unexamined Japanese Patent Publication No. 48-661
92, JP-A-53-14753, JP-A-54-85298, etc.) have been proposed.

However, when manufacturing polyester, 200
It is normal to carry out the reaction at a high temperature of ~300°C, and in particular, during the polymerization reaction, there are problems such as coloring of the polymer due to deterioration of the dispersant, deterioration of polymer quality, generation of foreign substances, and contamination of the polymerization reaction system by the dispersant. A problem occurs.

Furthermore, even if a dispersant is used, it is difficult to sufficiently deagglomerate the fine particles, which will be described later, because of their high surface energy.

Therefore, methods for increasing the dispersion efficiency during slurry adjustment and improving the dispersibility of slurry are disclosed in JP-A-53-114894, JP-A-53-125495, and JP-A-54-12.
This is proposed in Publication No. 4098 and the like. however,
Even with these methods, disaggregation of fine particles was not always sufficient.

In addition, ball mills and attris are used to disperse pigments, etc. □
Dispersion using a grinder such as a grinder or a sand mill is also known, for example, in Japanese Patent Application Laid-Open No. 57'-28140, but these methods are not sufficient to break up the agglomeration of fine particles. However, it is not possible to eliminate the presence of coarse particles due to secondary aggregation, and on the contrary, the particles are crushed to become smaller than the target particle size, and the particle size distribution is also broadened. Although the reason for this is not clear, it is presumed that in conventional methods, the frequency of collisions between media particles is low, while the collision energy is high.

[Purpose of the invention]

The purpose of the present invention is to improve the above-mentioned drawbacks of the prior art, to dissolve the agglomeration of fine particles in the slurry, and to dissolve the particles into the polymer without causing problems such as coloring the polymer, inhibiting the polymerization reaction, and generating foreign matter. The present invention relates to a method for producing polyester in which fine particles are finely dispersed and does not contain aggregated coarse particles.

[Structure of the invention]

The object of the present invention is to prepare inert inorganic fine particles (A) having an average primary particle size of 5 μm or less in a solvent when producing a polyester from a dicarboxylic acid component and glycol. The slurry of inorganic fine particles (A) obtained by separating the particles (Bl) is stirred together with particles (B) having a diameter of 10 to 4000 times the diameter and an average particle size of 0.5 cm or less. Chilling is a method outside the production of polyester, which is characterized by adding it to the polyester production reaction system.

The polyester in the present invention may be any polyester that can be molded into fibers, films, or other molded products, such as polyethylene tereph, tallate, poly-1,4-cyclohexyne dimethylene, etc. Examples include terephthalate, polytetramethylene terephthalate, polyethylene 2,6-naphthalene dicarboxylate, and the like. Of course, these polyesters may be homopolyesters or copolyesters (components to be copolymerized include, for example, diol components such as diethylene glycol, propylene glycol, and polyalkylene glycol; Examples include adipicarboxylic acid components.

When the dicarboxylic acid component is a dicarboxylic acid, after an esterification reaction with a glycoyl, and when a dicarboxylic acid ester is used, after an esterification reaction with a glycol, the resulting prepolymer is polycondensed at high temperature under vacuum. Made of polyester.

It is also possible to carry out the polycondensation using the prepolymer itself as a starting material.

The inert inorganic fine particles with an average primary particle diameter of 5 μ or less in the present invention include metal oxides such as titanium dioxide, phosphorus, alumina, and zirconia, composite oxides such as kaolinite, talc, and zeolite, and carbonates such as calcium carbonate. , phosphates such as lithium phosphate, calunium phosphate, cal/rum sulfate,
Refers to inorganic compounds such as sulfates such as barium sulfate with an average primary particle size of 5μ or less. Among the inorganic compounds, titanium dioxide, kaolinite, talc, carbonate and barium sulfate are particularly preferred.

The average carbon particle diameter l'i must be 5μ or less, preferably 1
The thickness used is 3μ or less, more preferably 2μ or less, and if it is 5μ or less during synthesis, it can be used as is. On the other hand, in the case of a synthetic inorganic compound or a natural inorganic compound having a particle size of 5 μm or more, the compound is crushed and classified in advance so that the average primary particle size is 5 μm or less before use.

If the average primary particle diameter is larger than 5 μm, it is not preferable because it causes yarn breakage during spinning or causes coarse protrusions in a film.

The slurrying solvent used in the present invention includes water, methanol, ethanol, alcohols such as ethylene glycol,
Examples include hydrocarbons such as toluene, xylene, and pentane. It is particularly preferable to use the same glycol as the one used as the raw material for producing polyester, since this will cause less deterioration in the quality of the polymer, prevent contamination during the process, and facilitate ease of operation.

In the present invention, the inert inorganic particles (A) have a particle diameter of 10 to 4000 times the average primary particle diameter of the inert inorganic particles,
A slurry is prepared by stirring together with particles (B) having an average particle diameter of 0.5 or less. As the particles (B), particles of ceramics such as alumina and zirconia, glass, steel, etc. are used. Among them, theragus and glass small spheres are preferable.

The particle size of the particles (B) is inert 11. m particle (A)
10 to 4000 times the average primary particle diameter of
It must be 5 mm or less. Preferably 15
Particles with a particle size of ~5,000 times, more preferably I'f: 20-2,000 times are used, and particles (Tsuru's particle size is 0.3
Rtrrn or less is preferred, and more preferably 0.1 tone or less is used.

If the particle size of the particles (B) is smaller than 10 times the average primary particle size of the inert inorganic particles (A), separation from the slurry becomes difficult;
If it exceeds 0.5fi, even if it is less than twice that, the dispersion efficiency will be insufficient and the agglomeration cannot be dissolved.

The concentration of the slurry of inert inorganic particles (A) is 1 to 50% by weight
is preferable, more preferably 3 to 30 layers, most preferably 1
Or 5 to 25 weight percent weight reduction. If the slurry concentration is less than 1% by weight, the reactivity during polymerization may be inhibited, which is undesirable, and if it exceeds 50% by weight, the slurry viscosity will increase and dispersibility will become poor, which is undesirable. .

In addition, particles (B) used together with inert inorganic particles (A)
) is preferably 0.1 to 10 times the volume of the slurry, more preferably 0.3 to 5 times, and most preferably 0.5 to 2 times.
．． It is 0 times.

If the amount of particles (B) used is less than 0.1 times the amount of the slurry, the inert inorganic particles (A) will be insufficiently dispersed, which is not preferable, and if it is still more than 10 times the amount of the slurry, the power required for stirring will be reduced. This is not preferable because it becomes larger and furthermore, the effect of improving the dispersibility can no longer be seen.

The stirring treatment can be carried out using a normal stirring device, although it varies depending on the type of inert inorganic particles used, the average primary particle diameter, and the type and diameter of the particles (]3) used together. That is, a stirring device equipped with one or more stirring blades such as propeller blades, paddle-shaped tools, turbine blades, cross blades, disks, etc. is preferably used at a speed of 100j to 10,000 rpm.
m.

More preferably 300 to 5000 rpm, preferably 5
Stirring is carried out for minutes to 10 hours, more preferably for 50 minutes to 8 hours. The dispersion method may be either continuous processing or batch processing, but batch processing is more preferable. The slurry that has been subjected to the agitation treatment is filtered, decanted/poured, or otherwise used to separate the particles (B), and left as is. After removing the coarse particles remaining in the slurry by filtration or using a super decanter, etc., the polyester is added to the production reaction system.

The inorganic particle glycol slurry of the present invention can be added at any point in the polyester manufacturing process. It is preferably added before the start of the esterification or transesterification reaction, during the polymerization reaction, from the stage when the intrinsic viscosity of the polymer does not exceed 0.2 to the beginning of the polycondensation reaction.

〔Effect of the invention〕

As described above, in the present invention, inert inorganic fine particles (A) having an average primary particle diameter of 5 μ or less are prepared in a solvent, and particles (B) having a diameter 10 to 4000 times the average primary particle diameter of the particles (A) are prepared.
A method for producing polyester is characterized in that the particles (B) are separated and the resulting slurry of inert inorganic fine particles (A) is added to a reaction system for producing polyester. By applying this method, the dispersibility of the inert inorganic fine particles in the slurry is improved, and the amount of aggregated coarse particles present in the chilester is extremely small, making it possible to obtain a polymer that is finely dispersed down to the primary particle size. can.

Since the polymer obtained by the method of the present invention has excellent particle dispersibility, it exhibits an effect similar to that of raw coal when molded into fibers, films, molded articles, etc.

(1) Fewer yarn breaks during spinning and spinning, and
Contamination caused by wear or falling off of guides, etc. is reduced.

(2) There is less clogging of the poly-ma filter during the yarn spinning and film forming processes, and an increase in filtration pressure can be suppressed.

(3) There are fewer protrusions on the film, which prevents the generation of white powder due to falling off, etc., and reduces contamination during the manufacturing process.

(4) There are fewer coarse protrusions due to agglomerated coarse particles, and the fine irregularities and uniformity of the yarn and film surfaces are improved.

The present invention will be explained in more detail below using examples.

In addition, the physical properties in Examples were measured as follows.

A, average primary particle diameter It was measured by the BET method.

B. Particle size distribution in slurry Light transmission type centrifugal sedimentation type viscosity analyzer (Shimadzu C!P-5
0 type).

C. A small amount of aggregated coarse particles in the polymer was sandwiched between two cover glasses at 280°C.
After melt-pressing and quenching, microscopic observation was performed to determine that a plurality of primary particles aggregated together and the portions where the particle size became coarse were aggregated coarse particles.

Regarding the dispersibility of particles, aggregated coarse particles having a size exceeding four times the average primary particle size present in 1 m2 are observed and displayed using the following judgment.

Grade 1: Less than 10 aggregated coarse particles/WrM2 with a size more than 4 times the average primary particle diameter.

2nd class: 10 aggregated coarse particles with a size more than 4 times the average primary particle size are present at an angle of 1III+12 or more and less than 3°//WI2.

Grade 6: There are 30 or more 2 to 50 aggregated coarse particles with a size exceeding 4 times the average primary particle diameter and less than 2 each.

Grade 4: 50 or more aggregated coarse particles with a size exceeding 4 times the average primary particle diameter are present.

Polymers up to grade 2 can be put to practical use.

D, intrinsic viscosity 0-1 at 25°C using chlorophenol as a solvent
I added one.

Implementation 111 10 parts of calcium carbonate with an average primary particle size of 0.5μ, 0.4 parts of phosphoric acid, 0.4 parts of triethylamine, 100 parts of ethylene glycol, and 1 glass bead with a particle size of 100μ
50 parts were charged into a stirring device equipped with turbine blades, and 30 parts
The mixture was stirred at 00 rpm for 4 hours. After stirring, the glass beads were separated using a 400-mesh wire mesh to obtain an ethylene glycol slurry of calcium carbonate. The average diameter of calcium carbonate in the slurry was 0.52μ.

(dimethyl terephthalate) 100 parts, 65 parts of ethylene glycol and 0.4 parts of manganese acetate (140 parts)
The transesterification reaction was carried out at ~240°C. Next, 0.03 parts of antimony trioxide and 5 parts of the prepared calcium carbonate ethylene glycol slurry were added, and the
The polymerization reaction was carried out at 90°C under high vacuum, and after 160 minutes, the intrinsic viscosity was 0.62. A polymer with a softening point of 260°C was obtained.

When the dispersion state of particles in the polymer was observed, the number of aggregated coarse particles was 1/III++2, indicating a good dispersion state. Next, using this polyester, spinning was carried out in a conventional manner. The pressure rise of the spinning filter was 1-21 after 10 hours.

Subsequently, stretching was carried out in a conventional manner, and as a result, no yarn breakage was observed within 10 hours.

Example 2 Irregularity was adjusted in the same manner as in Example 1 except that calcium/umium carbonate having an average primary particle diameter of 0.5 μm was used and 300 parts of 50 μm beads were used as glass beads. The average diameter of calcium carbonate in the obtained slurry was 0.31μ. Using this slurry, a polymer was produced in exactly the same manner as in Example 1, with an intrinsic viscosity of 0.63 and a softening point of 260.5°C.
The polymer was obtained.

When the dispersion state of particles in the polymer was observed, the number of aggregated coarse particles was 2/2, indicating a good dispersion state.

Then, using this polyester, it was extruded into a sheet form from an extruder at 290°C, rapidly cooled to obtain an amorphous sheet, and then extruded in the longitudinal and transverse directions at a temperature higher than the glass transition point.
．． It was stretched 5 times to make a 25μ film. The surface roughness Hmax (
When μ) was determined, it was 0.12 μ, and no coarse protrusions were present, forming uniform minute protrusions.

Comparative Example 1 In Example 1, glass beads 15 with a particle size of 100μ
A slurry was prepared in the same manner as in Example 1 except that 0 part was not added. The average diameter of cal/rum carbonate in the resulting slurry was H3, 1 μ.

Using the obtained slurry, Nishite polyethylene terephthalate was produced in exactly the same manner as in Example 1, and after 180 minutes, a polymer having an intrinsic viscosity of 0.63 and a softening point of 259.2°C was obtained.

When the state of dispersion of particles in the polymer was observed, the number of aggregated coarse particles was 280/2, indicating that the state of dispersion was extremely poor.

Comparison implementation f! i112 Glass beads 1 with a particle size of 1.5 mn in Example 1
A slurry was prepared in the same manner as in Example 1 except that 50 parts of the slurry was used. The average diameter of the calcium carbonate in the obtained slurry was 1.8μ.

Using the prepared slurry, polyethylene terephthalate was prepared in the same manner as in Example 1, and after 170 minutes, a polymer having an intrinsic viscosity of 060 and a softening point of 259.5°C was obtained.

When the state of dispersion of particles in the polymer was observed, the number of aggregated coarse particles was 180 pieces/π2, indicating that the state of dispersion was poor.

Using the obtained polyester, spinning was carried out in the same manner as in Example 1. As a result, the pressure increase in the spinning filter was 2 in 5 hours.
0 to 301, clogging of the filter occurred.

Example 3 0.1 part of tetraethylammonium hydroxide, 100 parts of ethylene glycol, and 100 parts of glass beads with a particle size of 70 μm were added to 10 parts of kaolinite with an average charcoal particle size of 02 μm.
The mixture was stirred at 0 rpm for 5 hours. After stirring, the glass beads were separated using a 400 mt wire mesh to obtain an ethylene glycol slurry of kaolinite.

The average diameter of kaolinite in the slurry was 0.26μ. 65 parts of ethylene glycol and 0.1 part of calcium acetate were added to 100 parts of dimethyl terephthalate.
The transesterification reaction was carried out at 0 to 240°C. Then,
003 parts of andymon trioxide, 004 parts of phosphoric acid, and 5 parts of the prepared kaolinite ethylene glycol slurry were added, and a polymerization reaction was carried out under high vacuum at 250 to 290°C. After 160 minutes, the intrinsic viscosity was o, 65, Softening point 2598
℃ polymer was obtained.

When the dispersion state of particles in the polymer was observed, it was found that the number of aggregated coarse particles was 3/2, indicating a good dispersion state.

Comparative Examples 3 to 6 A slurry was prepared by changing the diameter of the glass beads used in Example 3, and a polycondensation reaction of polyethylene terephthalate was carried out. The average diameter of the slurry neutral olinite and the state of dispersion in the polymer are shown in Table 1.

Table 1

Claims (1)

[Claims] When producing polyester from a dicarboxylic acid component and glycol, inert inorganic fine particles (A) with an average primary particle size of 5 μ or less are mixed in a solvent with a diameter 10 to 4000 times the average primary particle size of the inorganic fine particles (A). A slurry of inorganic fine particles (A) obtained by stirring together with particles (B) having an average particle size of 0.5 mm or less and then separating the particles (B) is added to a polyester production reaction system. A method for producing polyester characterized by the following.