KR20030020348A - Saturated polyester with excellent crystalization property for molding - Google Patents

Abstract

PURPOSE: Provided is a saturated polyester resin excellent in crystallinity, which has improved productivity and mechanical properties such as tensile strength and flexural strength and can be used for forming. CONSTITUTION: The saturated polyester is produced by an interesterification or an esterification, a polycondensation, and a solid state polymerization using an aromatic dicarboxylic acid and a diol, wherein 5ppm-30wt%(based on the last saturated polyester) of inorganic particles are added to the process for producing the saturated polyester. The saturated polyester has a thermal cooling crystallization temperature(Tcc) of 185-245deg.C and a thermal heating crystallization temperature(Thc) of 90-150deg.C. The inorganic particle is one or at least two selected from silica, calcium carbonate, aluminum, alumina, china clay, and titanium oxide and has an average particle size of 3-100nm.

Description

Saturated polyester resin for molding with excellent crystallinity {SATURATED POLYESTER WITH EXCELLENT CRYSTALIZATION PROPERTY FOR MOLDING}

The present invention relates to saturated polyesters having excellent strength, abrasion resistance, heat resistance, and the like, which are used in various molded articles such as machinery, electrical and electronic products, aircraft structural materials, household products, general goods, and the like, and particularly, nano-sized particles are present in the polyester polymer. By extending the crystallization temperature range and increasing the crystallization rate to improve the molding processability, mechanical properties, and the like.

Saturated polyester is a linear thermoplastic polymer having an ester bond in the main chain, such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), etc., and has dimensional stability, weather resistance, and surface smoothness. It is widely used for molded products such as engineering plastics, synthetic fibers, films, containers, and housings because of its excellent appearance, transparency, and glossy appearance.

However, these saturated polyesters have a high melting point, a narrow crystallization temperature range and a slow crystallization rate. In particular, polyethylene terephthalate (PET) is stronger than polybutyl terephthalate (PBT), and thus has difficulty in molding and physical property variation. There are many problems in use due to the increase.

In general, the method of improving the crystallization rate of the synthetic resin to improve the mechanical properties is mainly used to synthesize the base resin and then add a nucleating agent to improve the crystallization temperature range and speed during melt extrusion or injection. For example, U.S. Pat.No. 6,319,576 proposes a method of increasing the crystallization rate by using an organic material, which is a nucleating agent during melt extrusion, but in this case, there is a disadvantage that the intrinsic properties of the resin may worsen because other organic materials are mixed. In addition, US Pat. No. 5,730,913 proposes a method of increasing the degree of crystallinity through temperature control during injection molding. In this case, the basic physical properties of the resin are relatively good, but the productivity is low and the quality deviation is large.

An object of the present invention is to add a nano-sized inorganic particles in the synthesis of saturated polyester resins to present in the polymer, thereby widening the crystallization temperature range and increasing the rate of crystallization, thereby improving productivity and physical properties in molding. To provide.

The present invention is characterized in that in the production of saturated polyesters by transesterification (or esterification), condensation polymerization and solid phase polymerization, nano sized particles are added at an arbitrary step in the range of 5 ppm to 30% by weight to react. The present invention relates to a saturated polyester production method and a saturated polyester obtained thereby, specifically below.

In the present invention, the saturated polyester is made of an aromatic dicarboxylic acid or ester forming derivative and a diol component such as ethylene glycol or butanediol as a main starting material, but may include another third component. At this time, one or two or more kinds selected from isophthalic acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid, phthalic acid, adipic acid, sebacic acid, etc. may be used as the aromatic dicarboxylic acid component. Phosphorus ethylene glycol, propylene glycol, butanediol, 1,4-cyclohexanedimethanol, neopentylglycol and the like can be used. The saturated polyester thus obtained includes polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate and the like.

The saturated polyester used in the present invention may include additives such as heat stabilizers, anti-broking agents, antioxidants, antistatic agents, ultraviolet absorbers, flame retardants, etc., if necessary.

In the present invention, when the saturated polyester is synthesized using the starting materials as described above, nano-sized inorganic particles are added, and the nano-sized inorganic particles should be kept in the nano-sized state in the reactant. In this case, it is preferable to use nano sized inorganic particles having a size in the range of about 3 to 100 nm, but when using less than 3 nm, there is a problem such that dispersion is difficult due to the surface tension of the particles. There is a problem of poor transparency.

In addition, the inorganic particles are preferably added to about 5ppm to 30% by weight (more preferably, 50ppm to 20% by weight) in the polymer, but when added to less than 5ppm almost no improvement in physical properties, more than 30% by weight City has a problem that particles are difficult to uniformly disperse in the polymer. Inorganic particles usable in the present invention include silica, calcium carbonate, aluminum, alumina, china clay, titanium oxide, and the like, and these may be used alone or in combination of two or more thereof.

Thus, according to the present invention, the saturated polyester to which the nano-sized inorganic particles are added has a thermal cooling crystallization temperature (Tcc) of 185 to 245 ° C and a thermal heating cryctalization temperature (Thc). It can be extended to the range of 90 to 150 DEG C, and the crystallization rate can be improved.

In general, the number of particles can be expressed by the following equation.

Nn = Mp / (Dp × Vn)

Where Nn is the number of particles, Mp is the specific gravity of the particle, and Vn is the volume of one particle.

In other words, as confirmed by the above equation, when the particle size decreases to the nanometer unit, it means that the number of particles (number of crystal nuclei) is greatly increased.

As described above, in order to improve the dispersibility of nano-sized inorganic particles, it is preferable to add the particles in a slurry state dispersed in a single substance such as water, ethylene glycol or butanediol, or a mixture of two or more, and the concentration of nano inorganic particles in the slurry Is preferably in the range of 1% to 30% by weight, more preferably in the range of 5% to 20% by weight. When the amount is less than 1% by weight, too much slurry is added, so that there are a lot of side reactions, and when it exceeds 30% by weight, the dispersibility of the particles is deteriorated. In general, the smaller the particle size is, the better it is to make the slurry at a lower concentration, and the larger the particle size, the higher the particle concentration in the slurry can be.

In the present invention, when adding the nano-sized particles, for example, it is also possible to add a phosphorous compound such as phosphoric acid, Tri Methy Phosphate (TPM), Tri Ethyl Phosphate (TEP), Tri Phenyl Phosphate (TPP), etc. In this case, the phosphorus compound may obtain an effect of improving the color of the resin. The addition amount of such a phosphorus compound is preferably adjusted in consideration of the equivalence ratio with the metal ions, but is preferably in the range of 200 to 10,000 ppm based on the content of phosphorus in the final polymer.

When the nano-size inorganic particle slurry is added during the synthesis of the polyester, it is important that the addition method is such that the nano-sized particles do not aggregate. In the present invention, the molar ratio (E / T) of ethylene glycol (EG) and terephthalic acid (TPA) or dimethyl terephthalate (DMT) may be about 1.8 to 2.5 in the DMT method, and about 1.3 to 2.5 in the TPA method. In order to improve particle dispersibility, there is no particular limitation in the present invention, but in the case of DMT (Dimethylterephthalate) method, when a slurry is dispersed in water, a large problem occurs in the reaction, such as ethylene glycol (EG) or butanediol (BD). It is preferable to disperse it into a liquid such as In the TPA (Terephthalic Acid) process, even if some water is contained in the slurry, there is no big problem in the reaction. However, in terms of particle dispersion, the TPA method is inferior in dispersibility to the DMT method.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

Example 1

100 parts by weight of dimethyl terephthalate (DMT) and 64 parts by weight of glycol (EG) were added to the reactor while stirring and 0.03 parts by weight of antimony trioxide and 0.06 parts by weight of manganese acetate tetrahydrate were dispersed in 3 parts by weight of ethylene glycol and added to the reactor. Next, the mixture was heated to 130 ° C. to 230 ° C., and subjected to transesterification for 4 hours, thereby making BHT (B-1). A slurry (S-1) was produced by filtering an ethylene glycol slurry containing 10 wt% silica particles having an average particle diameter of 50 nm with a filter having a size of 0.5 μm filtration pore. (B-1) At a temperature of BHT at about 235 ° C. 0.03 parts by weight of trimethyl phosphate (TMP) is diluted to 2 parts by weight of ethylene glycol relative to the final polymer. 5 minutes after the end of the trimethyl phosphate addition, the temperature of the reactant was brought to 235 ° C, and 20 parts by weight of the prepared (S-1) slurry was slowly added while maintaining the temperature at 235 ° C. Thereafter, the residual oil ethylene glycol was distilled off at atmospheric pressure to bring the molar ratio of ethylene glycol and dimethylene terephthalate to 1.4. The BHT was filtered through a filter having a 3 μm filtration hole, and while heating, the mixture was decompressed to 1.0 TORR over 60 minutes and subjected to a condensation polymerization reaction for 3 hours while heating up from 235 ° C. to 285 ° C. over 50 minutes. A polymer with a reactant temperature of 285 ° C. and an intrinsic viscosity (IV) of 0.63 was made and cut with a cutter from 0.013 g to 0.23 g per piece (P-1-1). Was about 2.0% by weight.

This chip (CHIP) was placed in a general solid-state polymerizer and subjected to solid-phase polymerization so that the intrinsic viscosity (IV) was 0.80 (P-1-2). The chip was fabricated in a twin screw melt extruder at an operating temperature of 250 ° C to 285 ° C.

Example 2

1 part by weight of the nanoparticle slurry (S-1) obtained in the same manner as in Example 1 was added to BHT at 235 ° C to carry out condensation polymerization to make a chip. At this time, the nanoparticle content contained in the chip was about 1,000 ppm (P-2-1). This chip was subjected to solid phase polymerization in the same manner as in Example 1 (P-2-2). Using this chip, a specimen was prepared in the same manner as in Example 1 in a twin screw melt extruder at an operating temperature of 250 ° C to 285 ° C.

Example 3

In Example 1, except that 10 wt% of ethylene glycol was used as nanoparticles, spherical silica particles having an average particle size of 15 nm, and the slurry was filtered through a filter having a pore size of 0.5 μm. The liquid chip (P-3-1) was prepared in the same manner as in Example 1. At this time, the nanoparticle content contained in the chip was about 2.0% by weight, and in the same manner, the specimens were manufactured at the operating temperature of 250 ° C to 285 ° C in the biaxial melt extruder.

Example 4

Solid chips (P-4-2) and specimens were prepared in the same manner as in Example 1 except that liquid chips (P-4-1) containing silicium particles having an average particle diameter of 15 nm were used. .

Example 5

100 parts by weight of terephthalic acid and 75 parts by weight of ethylene glycol were added to the reactor and heated with stirring to raise the temperature from 30 ° C to 230 ° C, followed by esterification for 6 hours to form BHT (Bis-β-Hydroxyethylene Terephthalate), followed by EG and TPA. 148.6 parts by weight of the slurry having a molar ratio of 1.3 was added over 2 hours, followed by further reaction while maintaining the temperature at 230 ° C. for 1 hour and 30 minutes. Subsequently, 148.6 parts by weight of the produced BHT was filtered through a filter having a 3.0 μm filtration hole and transferred to a condensation polymerization reactor. After completion of this solution, 0.02% by weight of phosphoric acid was added to the final polymer, and after 5 minutes, 0.015% by weight of antimony trioxide was diluted with a small amount of ethylene glycol and then spherical silica with an average particle size of 15 nm. A slurry (S-2) prepared by making a 10 wt% slurry in ethylene glycol using a particle and filtered through a filter having a 0.5 μm pore size was added to 20 parts by weight of BHT at 230 ° C. as in Example 1, in 60 minutes. The pressure was reduced to 1.0 TORR, and at the same time, the temperature was raised from 230 ° C to 285 ° C over 50 minutes. In this state, a polycondensation reaction was carried out for 3 hours to produce a polymer having a temperature of 285 ° C. and an intrinsic viscosity (IV) of 0.63, which was cut from 0.013 g to 0.23 g per piece (P-5). At this time, the content of nanoparticles contained in the chip was about 2.0% by weight.

This chip (CHIP) was placed in a general solid-state polymerizer and subjected to solid-phase polymerization (P-5-2) with an intrinsic viscosity (IV) of 0.78. Then, the chip was tested in a twin screw melt extruder at an operating temperature of 250 ° C to 285 ° C. Was produced.

Example 6

Silica having an average particle size of 15 nm contains 1,000 ppm of the particles, making BHT, and then adding the phosphorus-based flame retardant in the amount of 3000 ppm based on the number of people. 1), a solid chip (P-6-2) and a specimen were produced.

Example 7

A solid chip (P-7-2) and a specimen were fabricated in the same manner as in Example 5 except that the liquid chip (P-7-1) containing 30 wt% of silicide particles having an average particle diameter of 3 nm was prepared. It was.

Example 8

A solid chip (P-8-2) and a specimen were prepared in the same manner as in Example 5, except that a liquid chip (P-8-1) containing 5 ppm of silicide particles having an average particle diameter of 3 nm was prepared.

Example 9

A solid chip (P-9-2) and a specimen were prepared in the same manner as in Example 5 except that the liquid chip (P-9-1) containing 5% by weight of silicide particles having an average particle diameter of 100 nm was manufactured. It was.

Example 10

100 parts by weight of terephthalic acid and 75 parts by weight of butanediol were added to a reactor, heated with stirring, and heated to 30 ° C. to 230 ° C., followed by an esterification reaction for 4 hours to produce BHBT (Bis-β-Hydroxybuthylene Terephthalate). At this time, the catalyst used 0.04% by weight of monobutyl tin oxide (MBTO) relative to the final polymer and 0.02% by weight of tetrabutyl titanate (TBT) relative to the polymer. Thereafter, 175 parts by weight of Bis-β-Hydroxybuthylene Terephthalate (BHBT) produced was filtered with a filter having a 3.0 μm filtration hole, and then 0.02% by weight of phosphoric acid was added to the polymer after condensation polymerization. The TBT was added to dilute a small amount of butanediol, and the 3 nm-sized silica particles were diluted in butanediol and added to 0.5 wt% of the polymer as in Example 5. Thereafter, the pressure was reduced to 1.0 TORR in 60 minutes, and at the same time, the temperature was raised from 230 ° C to 245 ° C over 50 minutes. In this state, a polycondensation reaction was conducted for 3 hours to produce a polymer having a temperature of 248 ° C. and an intrinsic viscosity (IV) of 0.90, which was cut from 0.013 g to 0.23 g per piece (P-11-). One). Using this chip, the specimen was fabricated in the twin screw melt extruder at the operating temperature of 225 ℃ to 250 ℃.

Comparative Example 1

100 parts by weight of terephthalic acid and 75 parts by weight of ethylene glycol were added to the reactor and heated with stirring to raise the temperature from 30 ° C. to 230 ° C., followed by esterification for 6 hours to produce BHT, followed by 148.6 weight slurry of EG and TPA molar ratio of 1.3. After the addition of the unit over 2 hours, the reaction was carried out while maintaining the temperature at 230 ° C. for 1 hour 30 minutes. Thereafter, 148.6 parts by weight of the produced BHT was filtered through a filter having a 3.0 µm filtration hole, and the solution was transferred to a condensation polymerization reactor. After completion of this solution, 0.02% by weight of phosphoric acid was added to the final polymer. After 5 minutes, 0.015% by weight of antimony trioxide was diluted in a small amount of ethylene glycol, and then decompressed to 1.0 TORR in 60 minutes. At the same time, the temperature was raised from 230 ° C to 285 ° C over 50 minutes. In this state, a polycondensation reaction was conducted for 3 hours to produce a polymer having a reaction temperature of 285 ° C. and an intrinsic viscosity (IV) of 0.63, which were cut from 0.013 g to 0.23 g per piece (P-11-). One).

This chip (CHIP) was placed in a general solid-state polymerizer and subjected to solid-phase polymerization so that the intrinsic viscosity (IV) was 0.80 (P-11-2) .The chip was then placed in a twin-screw melt extruder at an operating temperature of 250 ° C to 285 ° C. Produced.

Comparative Example 2

A slurry was prepared using silica particles having an average particle diameter of 200 nm instead of an average particle size of 15 nm, and the same procedure as in Example 5 was carried out, wherein the content of the nano silica contained in the chip was 5.0 wt%.

Comparative Example 3

A liquid chip (P-13-1) and a specimen were prepared in the same manner as in Example 10 except that silica particles were not added.

[Comparative Example 4]

The liquid chip was prepared in the same manner as in Example 5 except that 100 ppm of silica particles having an average particle size of 2 nm were used, but solid phase polymerization was carried out due to the presence of foreign matter having a size of about 3 mm in the chip. Did not do it.

The physical properties of the polymers obtained in the above examples and comparative examples were measured and shown in the following "Table 1" and "Table 2".

As shown in the above table, when the nano-sized particles are dispersed in the polymer, the result of DSC analysis shows that the crystallization temperature range of the crystalline polymer is up to 145 ° C while the crystallization temperature range (Thc-Tcc) of the general polymer is about 20 ° C. You can see that it extends to.

As can be seen from the above examples and comparative examples, the present invention obtains the effect of expanding the crystallization temperature range of the polymer by increasing the crystallization temperature of the polymer and increasing the crystallization rate by improving the productivity and mechanical properties by dispersing the nano-sized inorganic particles in the saturated polyester polymer. Can be. Therefore, the saturated polyester obtained in accordance with the present invention is excellent in crystallinity and physical properties, it is possible to produce a variety of molded articles having excellent properties by various molding methods such as injection, extrusion.

Claims (4)

Saturated polyesters produced by aromatic dicarboxylic acid and diol as main components through transesterification or solidification polymerization through transesterification or esterification reaction, in which the average particle size is 3 nm to It is obtained by adding and reacting inorganic particles in the range of 100 nm size so as to contain 5 ppm to 30% by weight in the final saturated polyester, and the melt cooling crystallization temperature (Tcc) is in the range of 185 ° C to 245 ° C and the elevated temperature crystallization temperature (Thc ) Is in the range of 90 ℃ ~ 150 ℃ saturated polyester excellent in crystallinity. The saturated polyester for molding having excellent crystallinity according to claim 1, wherein the inorganic particles are a single component or two or more composite components of silica, calcium carbonate, aluminum, alumina, china clay, and titanium oxide. The saturated polyester for molding having excellent crystallinity according to claim 1, wherein the phosphorus-based flame retardant is contained in a range of 200 ppm to 10,000 ppm based on the content of phosphorus in the saturated polyester. The saturated polyester for molding having excellent crystallinity according to claim 1, wherein the saturated polyester is selected from polyethylene terephthalate, polybutylene terephthalate and polytrimethylene terephthalate.