JPH0316378B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for dispersing fine particles. More specifically, the present invention relates to a method for dispersing fine particles that provides improved particle dispersibility when fine particles insoluble in a reaction mixture made of a molten condensed thermoplastic polymer are added and dispersed in the reaction mixture.

Thermoplastic polymers such as polyester and polyamide have many excellent properties and are therefore widely used in fibers, films, and the like. however,
Fine particles are added and dispersed into synthetic fibers and films made of such thermoplastic polymers for various purposes. For example, such synthetic fibers do not have a very good texture compared to natural fibers, and they also have poor hygroscopicity, water absorption, and color depth and clarity compared to natural fibers and cellulose fibers. It has some disadvantages compared to others.

Conventionally, as a measure to eliminate these drawbacks, insoluble inorganic fine particles are present in synthetic fibers,
A method has been proposed in which the fine particles are then eluted to make the synthetic fiber porous.

It is particularly desirable for the fine particles used in this method to be water-soluble in order to facilitate the subsequent elution process, but as stated in Japanese Patent Publication No. 43-16665, particles that are essentially water-soluble It has been extremely difficult to use it in practice because it easily forms coarse particles in thermoplastic polymers and causes trouble in the thread-spinning and film-forming processes or higher-order processing processes.

In order to establish an addition and dispersion method for obtaining a thermoplastic polymer in which water-soluble fine particles are finely dispersed, the present inventor developed a system using polyethylene terephthalate as the thermoplastic polymer and Mg 5-Na sulfoisophthalate as the water-soluble fine particles. A detailed study was conducted. As a result, coarse particles were easily formed in the method of adding an ethylene glycol slurry of Mg 5-Na sulfoisophthalate into a molten reaction mixture of polyethylene terephthalate, which means that Mg 5-Na sulfoisophthalate itself The main cause is that particle aggregation is extremely large due to strong ionicity, but in addition to this,
Even if the ethylene glycol slurry of Mg 5-Na sulfoisophthalate is subjected to high-speed stirring treatment, settling treatment, etc. to remove coarse particles,
We learned that the cause of this is that partial dissolution and recrystallization occurs due to the influence of trace amounts of moisture in the slurry, resulting in the formation of coarse particles.

As a result of the inventor's earnest efforts to establish an addition and dispersion method free from such drawbacks, the inventors have made the following efforts: By adding Mg 5-Na sulfoisophthalate in the form of a water-containing glycol solution to the reaction mixture in a molten state,
After learning that finely dispersed particles precipitate, we conducted a more detailed study on this system, and surprisingly found that
5-Na sulfoisophthalate is added in the final polyethylene terephthalate by showering a water-containing glycol solution of Mg 5-Na sulfoisophthalate into the molten reaction mixture through a nozzle with many small holes. It was discovered that Mg isophthalate becomes fine particles and its dispersibility is dramatically improved. As a result of further studies based on this knowledge, the present inventor found that by selecting an appropriate solvent, the present method could be applied to a wider range of polymer reaction mixtures and fine particles insoluble in the reaction mixture. , has completed the present invention.

That is, in the present invention, when adding and dispersing insoluble fine particles into a reaction mixture consisting of a condensed thermoplastic polymer in a molten state, the fine particles are dissolved in a solvent, and the dissolved solution is added to the reaction mixture. This is a method for dispersing fine particles.

In the method of the present invention, the objects to which fine particles are added are reaction mixtures during the production of condensed thermoplastic polymers in which the synthesis reaction is carried out in the molten state, such as polyesters such as polyethylene terephthalate and polybutylene terephthalate, nylon 66 and nylon 6 such as polyamide, block polyetherester, block polyetheramide, block polyesteramide, polycarbonate, etc.
Various molten reaction mixtures can be mentioned.

The fine particles used in the present invention are not particularly limited as long as they are insoluble in the reaction mixture to be added and a suitable solvent is present. Particles that are essentially soluble in the reaction mixture do not require the use of the method of the invention, nor can the method be applied to particles for which a suitable solvent is not present. Examples of the fine particles that can be used in the present invention include organic carboxylates, organic phosphonates, organic phosphinates, organic phosphates, organic phosphites, organic sulfonates, and organic sulfinates. , organic acid metal salts such as organic borates, inorganic acid metal salts such as phosphates, phosphites, borates, sulfates, acid salts, carbonates, bicarbonates, and metal halogens such as chlorides. Examples thereof include compounds, chelate compounds such as oxalic acid complex salts, metal hydroxides, metal oxides, etc. Among these, water-soluble ones are particularly preferred.

As the solvent used in the present invention, any solvent can be used as long as it can dissolve the above-mentioned fine particles, but it is particularly preferable to use a solvent that does not have an adverse effect on the reaction mixture. For example,
Water, alcohols, glycols, phenols, amines, caprolactams, and mixtures thereof are preferable, and among them, raw materials and product components of the reaction mixture or those that can be easily removed from the system during the reaction are used. It is particularly preferable to do so.

In the present invention, there is no need to adopt any special method to dissolve the above-mentioned fine particles in the above-mentioned solvent.
Any known dissolution method can be used. The dissolved concentration can be within a very wide range and may be appropriately determined by taking into account the size and shape of the device, the amount of fine particles added, etc.

The solution thus obtained must be sprinkled into the reaction mixture. If it is simply added to the reaction mixture from the addition pipe, coarse agglomerated particles will be formed.
The purpose of the present invention cannot be achieved.

In order to spray the solution into the reaction mixture in the present invention, it is sufficient to attach a porous shearing nozzle or a droplet sprayer to the tip of the solution input pipe, or simply install a baffle plate or cloth at the pipe opening or its tip. (cross), wire mesh, etc. can be simply attached. Furthermore, a method of connecting a ring-shaped pipe or T-shaped pipe having a slit or a plurality of small holes to the input pipe can also be adopted.

The droplet spraying methods mentioned above include (1) a two-fluid nozzle (atomizer), (2) a pressurized nozzle in which the liquid rapidly rotates in a swirl chamber and is sprayed through an orifice, and (3) a method using a high-speed rotating plate. can be given. In any case, it is necessary that the solution be added to the molten reaction mixture in the form of droplets, streams or films of dimensions sufficiently small compared to the diameter of the input pipe. By doing so, finely dispersed particles are precipitated in the reaction mixture, and a reaction product with excellent particle dispersibility can be obtained.

Further explanation will be given below with reference to Examples. Parts and % in the examples indicate parts by weight and % by weight, and the number of coarse aggregated particles in the obtained polymer was measured by the following method.

(Method for measuring the number of coarse agglomerated particles) Prepare a preparation by melting and pressing approximately 2 mg of precisely weighed polymer into a circular thin film with a diameter of approximately 1 cm between two cover glasses, and magnify it 200 times with an optical microscope to measure the diameter. The total number of coarsely aggregated particles with a size of 10μ or more was counted, and the number of coarsely aggregated particles was determined according to the following formula.

Number of coarsely aggregated particles = total number of coarsely aggregated particles/polymer weight (
Example 1 100 parts of dimethyl terephthalate, 60 parts of ethylene glycol, and 0.06 parts of calcium monohydrate were placed in a transesterification tank, and the mixture was heated under a nitrogen gas atmosphere for 4 hours.
The transesterification reaction was carried out while raising the temperature from 140°C to 230°C and distilling the generated methanol out of the system. Subsequently, 0.06 parts of trimethyl phosphate and 0.04 parts of antimony trioxide were added to the resulting reaction product, followed by 10% of Mg 5-Na sulfoisophthalate.
10 parts of ethylene glycol-water mixed solution (ethylene glycol: water = 85:15) was poured into a small hole with a pore diameter of 1.5 mm.
Added to the reaction product compound being stirred by a paddle-type stirrer at a peripheral speed of 3 m/s through a shearing nozzle with 103 holes in a staggered pattern with a pitch of 10 mm at a linear velocity of 70 cm/s. After that, it was transferred to a polymerization can. Then from 760mmHg to 1mmHg over 1 hour
At the same time, the temperature was raised to 285°C over 1 hour and 30 minutes. Under reduced pressure of 1 mmHg or less, polymerization temperature 285℃
Polymerize for another 3 hours, for a total of 4 hours and 30 minutes, until the intrinsic viscosity
0.658 and a softening point of 261°C was obtained. The number of coarse aggregated particles in this polymer was 0.5 particles/mg.

Comparative Example 1 A 10% ethylene glycol-water mixed solution of Mg 5-Na sulfoisophthalate was added directly from the 1/2-inch input pipe at a linear input speed of 70 cm/sec without using the shearing nozzle used in the example. The same procedure as in the example was carried out except for the following. The number of coarse aggregated particles in the obtained polymer was 12 particles/mg.

Example 2 100 parts of dimethyl terephthalate, 92 parts of 1,4-butanediol, and 0.05 part of titanium tetrabutoxide are charged into a transesterification tank, and the temperature is raised from 140°C to 170°C over 3 hours under a nitrogen gas atmosphere to generate. The transesterification reaction was carried out while methanol was distilled out of the system. Then a 25% aqueous solution of potassium-aluminum oxalate K ₃ [Al(C ₂ O ₄ ) ₃ ]
12 parts were added through the same shearing nozzle as in Example 1 at an input linear velocity of 85 cm/sec to the reaction mixture being stirred at a circumferential velocity of 3 m/sec by a paddle stirrer, and then transferred to a polymerization vessel. did. Next, the reaction was carried out for 30 minutes at normal pressure while raising the temperature to 245℃, and then for 1 hour.
The pressure was reduced from 760 mmHg to 1 mmHg, and polymerization was further carried out for 2.5 hours at a polymerization temperature of 245°C under reduced pressure of 1 mmHg or less to obtain a polymer having an intrinsic viscosity of 0.875 and a softening point of 226°C. Potassium-aluminum oxalate is uniformly dispersed in this polymer with an average particle size of approximately 0.5 μm, and the number of coarse aggregated particles in the polymer is 3/3.
It was mg.

Comparative Example 2 Without using the shearing nozzle used in Example 2, a 25% aqueous solution of potassium-aluminum oxalate was directly introduced from the 1/2 inch input pipe at the same input linear speed and stirring circumferential speed as in Example 2. The same procedure as in Example 2 was carried out except that it was added to.
Potassium-aluminum oxalate was uniformly dispersed in this polymer with an average particle size of approximately 0.8 μm, but the number of coarse aggregated particles in the polymer was 50.
The amount was as high as 1/mg.

Example 3 250 parts of ε-caprolactam and 1 part of titanium oxide slurry (lactam/water = 80/20, TiO ₂ concentration 15
%) into an autoclave, and then 4 parts of a 20% aqueous solution of potassium carbonate was placed at a position 5 mm from the tip of a 1/2-inch inner diameter input pipe using a circular nozzle with a diameter of 10 mm attached to the tip of the injection pipe, and then injected into an autoclave with a diameter of 8 mm, an inner diameter of 3 mm, and a thickness of 3 mm. 2mm
A donut-shaped baffle plate is welded and fixed with three legs (diameter 3 mm) through a circular nozzle at a linear velocity of 30.
cm/sec into ε-caprolactam in a molten state at 90°C under stirring. Then steam pressure 3.5
Kg/cm ² , after stirring for 3 hours at a reaction temperature of 265°C,
The pressure was returned to normal pressure to obtain an initial polymer. Subsequently, a polycondensation reaction was performed for 1 hour and 40 minutes under a nitrogen flow, followed by discharging, cutting, washing with hot water, and drying with high temperature nitrogen to reduce the moisture content to 0.03% and the intrinsic viscosity.
1.34, terminal primary amine [NH ₂ ] 45 gram equivalents/
10 ⁶ g of a polymer having a terminal carboxy group [COOH] of 48 gram equivalents/10 ⁶ g was obtained. Potassium carbonate was uniformly dispersed in this polymer with an average particle size of about 0.4 μm, and the number of coarse aggregated particles in the polymer was 0.5 particles/mg.

Comparative Example 3 Example 3 was carried out in the same manner as in Example 3, except that the donut-shaped baffle plate welded to the front of the circular nozzle at the tip of the input pipe was not attached. Potassium carbonate was uniformly dispersed in the obtained polymer with an average particle size of about 0.4 μm, but the number of coarse aggregated particles in the polymer was as large as 12 particles/mg.

Example 4 100 parts of bisphenol A, 96 parts of diphenyl carbonate, and 0.00015 parts of Na salt of bisphenol A as a transesterification catalyst were charged into a transesterification tank, and the reaction temperature was 200°C for 140 minutes under a reduced pressure of 100 mmHg in a nitrogen gas atmosphere. A transesterification reaction was carried out and 75 parts of phenol was distilled out. Next, the pressure inside the transesterification tank was returned to normal pressure using nitrogen gas.
4 parts of a 25% aqueous solution of Mg 5-Na sulfoisophthalate was passed through the same showering nozzle as in Example 1, and was mixed with a paddle type stirrer at a linear input speed of 30 cm/sec.
It was added to the reaction product which was being stirred at a circumferential speed of m/sec and then transferred to a polymerization vessel. Next, add a 1mm polymerization can.
The pressure was reduced to Hg and the temperature was raised to 290°C at the same time. 1mm
Polymerization was carried out for 280 minutes at a polymerization temperature of 290°C under reduced pressure below Hg to obtain a polymer with a relative viscosity of 1.302. The number of coarse aggregated particles in this polymer was 2 particles/mg.

Comparative Example 4 The procedure was carried out except that a 25% aqueous solution of Mg 5-Na sulfoisophthalate was added directly from the 1/2-inch input pipe at a linear input speed of 30 cm/sec without using the shearing nozzle used in Example 4. Example 4
I went in the same way. The relative viscosity of the obtained polymer is
1.308, and the number of coarse aggregate particles in the polymer is 38.
It was 1/mg.

Claims (1)

[Claims] 1. When adding and dispersing insoluble fine particles into a reaction mixture consisting of a molten condensed thermoplastic polymer, the fine particles are dissolved in a solvent and the dissolved solution is sprinkled into the reaction mixture. A method for dispersing fine particles characterized by: