JPS6131428A - Production of polyester - Google Patents

Abstract

PURPOSE:To obtain the titled polymer having improved running property, abration, resistance and surface characteristics, by esterifying a terephtalic acid with a glycol, dispersing particles having a specific surface area in an alkali, adding the resultant dispersion to the ester, and depositing an alkali metal-containing particles in polycondensation. CONSTITUTION:Terephthalic acid or an ester-forming derivative, e.g. eimethyl terephthalate, and a glycol, e.g. eyhylene glycol, are subjected to ester interchange or esterification reaction, and then polycondensation is subsequently carried out to produce a polyester. In the process, a particulate material, insoluble in the system, and having >=5m<2>/g specific surface area is dispersed in an alkali metal compound in an amount of 10-100wt% based on the particulate material, and the resultant dispersion is then added to any time before starting the polycondensation reaction, and particles containing one or more alkali (earth) metals as part of the constituent components are deposited in the polycondensation reaction to afford the aimed polymer.

Description

[Detailed Description of the Invention] E-Technical Field] The present invention is directed to improving running properties, abrasion resistance,
This invention relates to a method for producing ljj of polyester with improved surface properties.

[Prior art and its problems 1 Polyester in general, and polyethylene terephthalate in particular, has excellent mechanical properties, heat resistance, weather resistance, electrical insulation, and chemical resistance, so it is used not only as textiles for clothing and industrial purposes, but also as films for magnetic tapes and photographs. It is widely used in the film field such as electric insulation film, capacitor film, etc.

When polyester is used in the film field, it must be easy to pass through the molding processes of melt extrusion, stretching, and heat treatment, or when forming a film, it must be easy to wind, cut, apply magnetic layers to the surface, and incorporate into electrical parts. , from the value of the final product such as slippage, abrasion resistance, and surface properties of film products, we manufacture a polyester composition containing fine particles, which gives the surface a moderate eIJ convexity to give surface smoothness, and film formation. It is common practice to improve film flow and improve surface properties and abrasion resistance.

Polyester compositions containing such fine particles include: - Polyester compositions obtained by adding and blending inert, insoluble fine particles such as silicon oxide, titanium dioxide, lucium carbonate, talc, clay, and organic polymers. , ■ Polyester compositions obtained by precipitating fine particles containing alkali, alkaline earth metal, and other metal compounds added to the polyester synthesis system as well as phosphorus compounds as part of their constituent components during the polymerization reaction process. Are known.

However, such known fine particle-containing polyester compositions have the following problems, and especially when formed into a film, their slipperiness, abrasion resistance, surface condition, film formability, etc. are not satisfactory. It wasn't.

That is, in the polyester composition obtained by the above-mentioned method of adding insoluble fine particles, the particle system is non-uniform due to the difficulty in making the added particles fine and coarse particles coexisting due to agglomeration of particles.

In addition, coarse protrusions caused by coarse particles coexist, causing problems such as fish eyes and dropouts.Furthermore, in order to prevent fine particles from agglomerating together, dispersants that are added often interfere with the heat resistance and electrical properties of these polyesters. This results in disadvantages such as deterioration of characteristics. Therefore, JP-A-53-1
In order to finely disperse the particles, Japanese Patent No. 2595 discloses an example in which the additive particles are finely dispersed using a special stirring blade and are present in the polyester, but the purpose has not been fully achieved.

On the other hand, in polyester compositions containing particles obtained by the so-called fine particle precipitation method described in (2) above, increasing the particle content makes it difficult to control the particle size of the precipitated particles, and furthermore, increasing the particle amount causes agglomeration of the particles. J: Problems such as an increase in coarse particles occur. For example, JP-A-53-41
Although Patent No. 03 discloses an example of precipitated particles containing lithium element, it has not yet shown sufficient effects in the above-mentioned applications.

Particularly in recent years, the use of magnetic tapes has grown significantly, and magnetic tapes have come to be used in many applications such as audio tapes, video tapes, and memory tapes, and the required properties are becoming increasingly sophisticated.

Furthermore, it is necessary to reduce the thickness of the magnetic tape in order to reduce the size and increase the density, and there is an increasing demand for making the irregularities on the film surface more uniform and fine.

Furthermore, by blending it with a polyester that does not contain particles or has a small particle content, a polyester film of 19
．． l Adding favorable surface properties to polyester film,
In order to produce molded products with excellent slipperiness, raw materials are required that are free of coarse particles and contain a large amount of fine particles. However, the finer these particles are and the larger the amount of particles, the more likely coarse particles are to be produced due to aggregation of particles.

[Objective of the Invention 1] In view of the above-mentioned circumstances, the present inventors have found that when a film having a large amount of uniform fine particles is formed into a film, the wear resistance of the film is
The present invention was completed after studying a method for producing polyester that is effective in improving slipperiness.

[Structure of the Invention] The object of the present invention described above is to perform a transesterification or esterification reaction between terephthalic acid or its ester-forming derivative and a glycol, and then to perform a polycondensation reaction to produce a polyester. At any point before the start, the specific surface area insoluble in the system is 5* 2 /a
The above particulate matter is added after being dispersed using 10 to 100% by weight of an alkali metal compound, and one or more alkali metals or alkaline earth metals are further added to the particulate matter as a constituent component during the polycondensation reaction. This can be achieved by a polyester production method characterized by precipitating particles that are part of the polyester.

Polyester in the present invention is mainly composed of polyethylene terephthalate that can be molded into fibers, films, and other molded products, and may be homopolyester or copolyester.
For example, diethylene glycol, propylene glycol,
neopendel glycol, polyalkylene glycol,
Diol components such as P-cyclohexane dimetatool, 5-sodium sulforesorcin, dicarboxylic acid components such as adipic acid, sebacic acid, phthalic acid, isophthalic acid, 2,6-naphthalene dicarboxylic acid, trimellitic acid, pyromellitic acid, etc. Examples include polyfunctional dicarboxylic acid components and P-oxyethoxycarboxylic acid components.

After the esterification reaction with glycol if the dicarboxylic acid component is a dicarboxylic acid component, or after the transesterification reaction with glycol if the dicarboxylic acid ester is a dicarboxylic acid component, the resulting prepolymer is subjected to a polycondensation reaction at high temperature and reduced pressure to form a polyester. do.

Depending on the type of particulate matter that is insoluble in the reaction system used in the present invention, it may affect the amount and particle size of particles containing alkali metals and/or alkaline earth metals and phosphorus compounds precipitated during the polycondensation reaction. give. Silicon dioxide, calcium carbonate, magnesium carbonate, aluminum silicate, talc, and titanium dioxide are used as particulate substances that are insoluble in the reaction system and are highly effective in obtaining polyester containing a large amount of fine and uniform particles, which is the object of the present invention. ,mica,
Examples include inorganic particles such as calcium phosphate and barium sulfate, crosslinkable resin powders such as crosslinked polyester, and organic fine particle powders such as Teflon powder.

Further, among the above particulate materials, silicon dioxide, calcium carbonate, aluminum silicate particles, etc. can be preferably used.

The specific surface area of particulate matter insoluble in the reaction system by the BET method is 5 tn'/! ] or more, but preferably 30 m2/(1 or more, 1000 m2/(1 or less), particularly preferably 80 tn'/(l or less)2, 800 m2/C
I or less.

If the specific surface area of the particulate matter insoluble in the reaction system is less than 5 m2/g, the particle size of the precipitated particles will be different from that of the precipitated particles, making it impossible to obtain a large amount of uniform, fine particles. The amount of inert particles used is preferably 0.005 to 2.0% by weight, more preferably 0.01 to 1.0% by weight, based on the total acid components constituting the polyester.

The alkali metal compounds used in the dispersion treatment of particulate matter include hydrides, alcolades, chlorides, hydrides, etc. of alkali metals such as lithium, sodium, and potassium.
Examples include carbonates, carboxylates, sulfates, and the like.

The amount of the alkali metal compound to be used needs to be in the range of 10 to 100 ffl% by weight, preferably 20 to 80% by weight, particularly preferably 30 to 60% by weight, based on the particulate matter.

If it is less than 10% by weight, a sufficient dispersing effect on particulate matter will not be obtained, and if it is more than 100% by weight, no further effect can be expected.

The dispersion treatment of the particulate material with an alkali metal compound is preferably carried out in a medium, and in view of the reaction after being added to the reaction system, it is preferable to carry out the dispersion treatment in ethylene glycol and prepare an ethylene glycol slurry. Ethylene glycol slurry is prepared using conventionally known preparation methods.
For example, a method such as fine dispersion using a special stirring blade disclosed in Japanese Patent Application Laid-Open No. 53-125495 is used.

In this case, an ethylene glycol slurry of particulate matter and an ethylene glycol solution of an alkali metal compound are separately prepared and then mixed and dispersed.Alternatively, particulate matter is introduced into an ethylene glycol solution of an alkali metal compound. Before adding it to the polyester polycondensation system, dispersion treatment is performed by any method, such as finely dispersing it by adding it to the polyester polycondensation system, or adding the particulate matter and the alkali metal compound to ethylene glycol at the same time and finely dispersing it. It is necessary.

The particulate matter dispersed using the alkali metal compound may be added to the reaction system in the ethylene glycol slurry at any time from -10 to the start of the polycondensation reaction.

Alkali metal for producing precipitated particles used in the present invention,
Alkaline earth metal compounds include alkali metals, alkaline earth metal hydrides, alcolades, chlorides, hydrides,
Examples include carbonates, carboxylates, sulfur*tn, and the like.

Specific examples include lithium acetate, lithium chloride, sodium acetate, calcium acetate, and magnesium chloride. Among them, calcium and lithium hydroxides and aliphatic carboxylic acids produce large amounts of precipitated particles, suppressing side reactions,
In addition, it is preferably used because of the ease of post-processing. The amount of these metal compounds to be used is preferably 0.01 to 2% by weight based on the total acid components constituting the polyester, and preferably at any time before the start of the polycondensation reaction, particularly preferably when the transesterification reaction or esterification reaction is substantially complete. It is added after the end of the reaction until the start of the polycondensation reaction.

The phosphorus compound used in the present invention may be selected from the group consisting of phosphoric acid, phosphorous acid, methyl esters thereof, ethyl esters, phenyl esters, halfesters thereof, phosphonic acids, phosphinic acids, or esters thereof. There are one or more types of The amount of phosphorus compound used is also related to the amount of metal compound used, but it is
Preferably 0.001 to 2% by weight, more preferably 0.001 to 2% by weight.
01-2% by weight. The timing of addition is esterification,
Alternatively, it is preferably added after the end of the transesterification reaction, and at any time before the start of the polycondensation reaction.

Further, in the present invention, the weight ratio of particulate matter insoluble in the reaction system to precipitated particles precipitated in the reaction system is preferably 0.1 to 50, more preferably 0.3 to 30, and even more preferably 0.5. ~10.

Note that the precipitated particles were determined by Soft's method.

(Method for quantifying precipitated particles) Approximately 300 g of the polymer composition or film was collected, and 2.7 g of O-chlorophenol was added thereto, and the mixture was stirred for 1 hour.
The temperature was raised to 00°C, and after the temperature was raised, the mixture was left as it was for another 1 hour to dissolve the polyester.

However, if the polymer portion is highly crystallized under these conditions, and if the polymer portion is not sufficiently dissolved, the melting process can be carried out using a sample obtained by dissolving the monopolymer composition and then rapidly cooling it under the above dissolving conditions. Next, a separation ultracentrifuge 401
Type 1 (newly manufactured by Hitachi) with rotor Rp method and rotor R1
After injecting 3 Qcc of the above solution per cell, the rotor was rotated at 450 rpm, and after confirming that there was no abnormal rotation, the rotor was evacuated and the particles were centrifuged.

The completion of separation is approximately 40 minutes later, and this is confirmed by the fact that the light transmittance at 375 millimicrons of the liquid after separation becomes a constant value that is higher than that before separation.

Before and after minutes, the supernatant liquid is decanted to obtain minute #1 particles.

Since the separated particles may be contaminated with polymer parts due to insufficient separation, O-chlorophenol at room temperature is added to the collected particles to homogeneously suspend them, and then the particles are centrifuged again.

This operation, which will be described later, involves drying the particles and then scanning the particle portion. Finally, the separated particles thus obtained were vacuum dried at 120° C. for 16 hours and weighed, and the amount of the particulate matter added to the polyester reaction system was removed from the amount to determine the amount between the precipitated particles.

In the present invention, the esterification reaction or the transesterification reaction includes a suitable amount of catalysts such as alkali metals such as lithium, sodium, and potassium, alkaline earth metals such as magnesium, calcium, strontium, and barium, and hydrides of curved lead and manganese. Alcoholades, chlorides and glycol-soluble salts of monocarboxylic acids are preferably used as catalysts. Particularly preferred examples include sodium acetate, escaped calcium acetate, strontium acetate, zinc acetate, manganese acetate, and 14-manganese chloride.

In addition, typical catalysts used for polycondensation of bishydroxyalkyl esters of aromatic dicarboxylic acids are glycol-soluble antimony or germanium compounds.
Specifically, antimony trioxide, antimony potassium tartrate,
Antimony oxychloride, germanium oxide, and the like are preferably used.

[Effects of the Invention] The polyester of the present invention is characterized in that it contains a large amount of uniform and fine precipitated particles, and has extremely few coarse particles compared to polyester obtained by conventional precipitated particle generation methods or addition methods.

When producing fibers and films from polyester, the following effects that could not be achieved with conventional products are achieved.

■ There is less clogging of filters during the process of melt molding into fibers and films, and films with good workability in post-processing steps can be obtained.

■ Even if the film is formed into an extremely thin film with a thickness of 3 microns or less, the film is still packed with many particles consisting of uniformly fine precipitated particles and particulate matter that is insoluble in the reaction system.
There is no blocking phenomenon between the films or between the film, the gold side L film, and the felt, and a polyester film is obtained which has excellent slipperiness, good surface properties, and excellent abrasion resistance with few particles falling off.

■ Furthermore, since the device contains uniform fine particles, it is extremely useful because there are no dropouts, uneven images, or skipping during playback when diluted.

The polyester obtained by the present invention can be preferably used not only for fibers such as multifilaments and staples, non-oriented, -axially oriented, and biaxially oriented films, but also for monofilaments and plastics.

The present invention will be explained in detail with reference to Examples below.

Incidentally, each characteristic value of the obtained polyester was measured according to the following method.

(A) Grain traces of particles in the polymer 20g of rank Boria was sandwiched between 2 coverslips 28
After melt pressing at 0°C and cooling, the particles were observed under a microscope and ranked based on the average particle diameter as follows.

A: Particle size less than 1.0 microns B: Particle size 1. O Mira 02 or more and less than 3 microns C: Particle size 3
Micron or more and less than 5 microns D: Particle size of 5 microns or more (B) Particle dispersion of particles in polymer 20 mo of polymer is sandwiched between two cover glasses 28
Melt press at 0°C, cool, observe with a microscope, 11III
The following judgment is made based on the number of coarse particles of 3 microns or more present in 112.

Class 1 = 10 coarse particles exceeding 3 microns/1111
Less than 112 exist.

2nd class = 10-30 coarse particles exceeding 3 microns/l
l11112 exist.

Grade 3: 30 coarse particles exceeding 3 microns/111 liters
Exists beyond I12.

(C) Intrinsic viscosity of polymer This is a value measured at 25°C using 0-chlorophenol as a solvent.

(D) Film Properties a) Film Abrasion Coefficient Measured using a slip tester according to ASTM-D-1894B method. Note that the coefficient of static friction was used as a measure of the slipperiness of the film.

b) Observe the surface of the film using a stylus roughness meter, and express the difference between the highest and lowest parts of the surface unevenness obtained in microns.

Example 1 A transesterification reaction was carried out using 10,011 parts of dimethyl terephthalate and 70 parts of ethylene glycol in a conventional manner using 0.09 parts by weight of calcium acetate as a catalyst, and the product was mixed with 0.03 parts by weight of antimony trioxide,・Silicon dioxide (well finely dispersed as a 10% by weight ethylene glycol slurry using 0.2 parts by weight of lithium acetate, 0.2 parts by weight of trimethyl phosphate, and 50% by weight of lithium acetate based on the particles) Specific surface area 200m'/
(1) 0.2 parts by weight was added and polymerized by a conventional method to obtain 1 q of polymer having an intrinsic viscosity of 0.632. The dispersibility of the particles in the polymer was first class, and the particle size was Parank, which was extremely good.

Comparative Example 1 After completing the transesterification reaction in Example 1, 0.3 parts by weight of lithium acetate and 0.3 parts by weight of trimethyl phosphate were added to the product.
The process was repeated in the same manner as in Example 1 except that only 2 parts by weight and 0.03 parts by weight of antimony trioxide were added to obtain an intrinsic viscosity of 10.6.
09 polymer was obtained. The dispersibility of the particles in the polymer was 3rd grade, and the particle size was C rank, which was not preferable.

Examples 2 to 6 and Comparative Example 2.3 Polyester compositions were prepared using the same methods as in Example 1, such as the amount of inert particles added and the source of precipitated particles, except that the type of inert particles was changed and the reaction was performed. Obtained. Table 1 shows the added powder species, particle size and dispersibility of the particles in the polymer.

(Leaving space below) Table 1 Comparative Example 4 A transesterification reaction was carried out using 0.09 parts by weight of calcium as a catalyst from 11 parts of dimethyl terephthalate and 70 parts by weight of ethylene glycol, and the product contained 0.0% of antimony trioxide. 0.03 parts by weight of lithium acetate, 0.03 parts by weight of lithium acetate, and 0.2 parts by weight of trimethyl phosphate were added, and polymerization was carried out by a conventional method to reach a torque value of a target viscosity. Next, the inside of the system was returned to normal pressure, and 10% by weight was added in advance.
Well-dispersed silicon dioxide (specific surface area 200vn2/!) as an ethylene glycol slurry with a concentration of 0
．． 2 parts by weight was added, ethylene glycol was distilled off while gradually reducing the pressure, and silicon dioxide was dispersed and mixed into the polymer to finally obtain a polymer with an intrinsic viscosity of 0.602. The particle size in the polymer was a double distribution of A and C ranks, and the dispersibility was also 3rd grade, which was preferable and not winter-like.

Example 7 After completing the transesterification reaction in Example 1, the product was mixed with 10 parts by weight of 0.06 parts by weight of lithium acetate, 0.03 parts by weight of phosphorous acid, and 80% by weight of lithium acetate based on the particles in advance. % concentration of ethylene glycol slurry (specific surface area 250
A polymer having an intrinsic viscosity of 0.611 was obtained in the same manner as in Example 2, except that 0.05 part by weight of m210) was added and reacted.

The particle size in the polymer is A rank, the particle dispersibility is 1st grade,
It was extremely desirable.

Comparative Example 5 The esterification reaction product was charged into an esterification reaction vessel equipped with a stirrer, a partial condenser, and a raw material inlet, and dissolved by heating at 250° C. in the presence of nitrogen gas. A 1-ethylene glycol slurry of terephthalic acid with a molar ratio of ethylene glycol to terephthalic acid adjusted to 1.20 was continuously supplied to the reaction vessel, water was distilled off, and an esterification reaction was carried out. 105 parts by weight of the esterified product (equivalent to 100 parts by weight of ethylene terephthalate units) was charged into a polycondensation reactor and maintained at 250°C.
．． 02 parts by weight of antimony trioxide, 0.025 parts by weight of antimony trioxide, silicon dioxide (specific surface area 200 m
0) was added and the pressure inside the system was gradually reduced to carry out a polycondensation reaction to obtain a polymer having an intrinsic viscosity of 0.611. 50 parts by weight of the boria and 50 parts by weight of the boria obtained in Comparative Example 1 were melt-kneaded and mixed at a temperature of 285° C. for 10 minutes to obtain a polymer with an intrinsic viscosity of 0.590. The particle size rank in the polymer showed a wide distribution of Δ to C, and the dispersibility was also tertiary, which was not preferable.

Example 8 1 q of the polyester composition obtained in Example 1 was added to 2 q by a conventional method.
Formed into a sheet at 90°C and longitudinally stretched at a magnification of 3 using a biaxial stretching machine.
．． After stretching at a transverse stretching ratio of 3 times and 3.4 times, heat treatment was performed at 215° C. to obtain a film with a thickness of 12 microns. Work stability during film formation was good, and there were no problems such as tearing due to straining. The obtained film had a coefficient of friction of 0.65, an average film surface roughness of 0.027 microns, and a maximum film surface roughness of 0.29, which were good.

Comparative Example 6 A film with a thickness of 12 microns was obtained in the same manner as in Example 4, except that the polyester composition of Comparative Example 1 was used in the same manner as in Comparative Example 1. The average roughness of the obtained film surface was 0.039 microns, and the maximum roughness of the film surface was 0.41 microns, which was not favorable in terms of film surface properties.

Example 9 A transesterification reaction was carried out using 100 parts by weight of dimethyl terephthalate and 70 parts by weight of ethylene glycol using 0.035 parts by weight of manganese acetate as a catalyst, and the resulting product was mixed with 0.03 parts by weight of antimony trioxide and phosphorus. 0.025 parts by weight of trimethyl acid was added and polymerized by a conventional method to obtain a polymer having an intrinsic viscosity of 0.620. After mixing 775 parts by weight of the poly and 25 parts by weight of the boria obtained in Example 1, a film having a thickness of 12 microns was obtained in the same manner as in Example 4. The coefficient of friction of the film was 0.87, the average roughness of the film surface was 0.018 microns, and the maximum roughness of the film surface was 0.18 microns, which were good.

Example 10 The esterification reaction product was charged into an esterification reaction vessel equipped with a stirrer, a partial condenser, and a raw material inlet, and dissolved by heating at 250° C. in the presence of nitrogen gas.

Ethylene glycol of terephthalic acid, whose molar ratio of ethylene glycol to terephthalic acid was adjusted to 1.20, was continuously supplied to the reaction vessel to distill off water and carry out an esterification reaction.

105 parts by weight of the esterified product (equivalent to 100 parts by weight of ethylene terephthalate units) was charged into a polycondensation reactor, maintained at 250°C, and 0.05 parts by weight of calcium acetate, 0.10 parts by weight of lithium acetate, and phosphorus were added. Using 0.15 parts by weight of trimethyl acid, 0.031 parts of antimony trioxide, and 50% by weight of lithium acetate based on the particles,
Well-finely dispersed silicon dioxide (specific surface M2O0yn'/1) as an ethylene glycol slurry at a concentration of % by weight
) 0.10 parts by weight was added, and the pressure inside the system was gradually reduced to carry out a polycondensation reaction.

The final reaction was carried out at 0.7 vsH (1,290°C for about 4 hours. The intrinsic viscosity of the obtained polymer was 0.612, the particle size in the polymer was palanque, and the particle dispersibility was first grade, which was good. Met.

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Claims (1)

[Claims] When producing a polyester by transesterifying or esterifying terephthalic acid or its ester-forming derivative with a glycol and subsequently carrying out a polycondensation reaction, at any point before the start of the polycondensation reaction, it is necessary to A particulate material having a specific surface area of 5 m^2/g or more is added by dispersing the particulate material with 10 to 100% by weight of an alkali metal compound, and then added to the particulate material by dispersing the particulate material with an alkali metal compound of 10 to 100% by weight, and further adding an alkali metal or alkaline earth during the polycondensation reaction. 1. A method for producing polyester, which comprises precipitating particles containing one or more of the similar metals as part of the constituent components.