KR100411843B1 - High viscosity polybutyleneterephthalate resin and its usage - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polybutylene terephthalate resin (hereinafter referred to as PBT) resin having excellent extrusion molding, wherein a tin compound such as monobutyl tin oxide, a siloxane compound such as polydimethylsiloxane, and a phosphorus compound are used as a catalyst in PBT resin. After the melt polymerization by addition, it is obtained by solid-phase polymerization in the form of a chip, which is high viscosity and has an extrudability enough to be applied to the optical fiber cladding tube in the melt flow properties can be useful for the optical fiber cladding tube.

Description

High viscosity polybutylene terephthalate resin and optical fiber coating tube made therefrom

The present invention relates to a polybutylene terephthalate (hereinafter referred to as PBT) resin having excellent extrusion molding and an optical fiber coated tube prepared therefrom. More particularly, the present invention relates to an excellent extrudability and melt flow index for an optical fiber tube. Index, measurement conditions: 250 ° C. × 2,160 g) The present invention relates to a polybutylene terephthalate resin satisfying 5 to 15 g / 10 min and an optical fiber coated tube prepared therefrom.

In recent years, the market for optical cables has been actively developed than copper cables as communication wires, and PBT resin is used as a very important material for optical fiber tubes. Therefore, many manufacturers are making great efforts to mass-produce high-viscosity PBT resins and to improve their characteristics in order to develop the market for optical fiber tubing.

PBT resins currently in use are manufactured through a process of increasing the viscosity to be applicable to the extrusion process by solid-phase polymerization using a base resin that has undergone melt polymerization, but still has basic extrusion moldability.

Normally, resins prepared through melt polymerization have carboxyl end groups of about 40 to 60 eq./10 ⁶ g, while solid phase polymerization lowers the end groups to 10 to 30 eq./10 ⁶ g. Raise the molecular weight. PBT high-viscosity resin prepared in this way has less carboxyl terminal group and shows better extrudability than low-viscosity resin (PBT resin) produced through melt polymerization, but it has high melt flow index (Melt Flow Index, 250 ℃ × 2,160g). It did not show the characteristic which is 5-15 g / 10min.

As a conventional melt polymerization technique, Korean Patent Publication No. 96-17779 discloses a method of adding boronite, phosphorus compounds, hindered phenol compounds, and thioether compounds as melt nucleating agents to melt polymerization, and Korean Patent Publication No. 96-22678 Korean Patent Publication No. 96-18281 discloses a method in which a phosphorus compound and a sulfur compound are added during melt polymerization in a solid phase polymerization. However, even in these methods, the melt flow index required by the present invention after solid phase polymerization cannot be obtained.

In addition, U.S. Patent No. 4,581,368 proposes a method of injecting an alkali metal or alkaline earth metal salt during melt polymerization, but in this case, the solidification rate of PBT decreases the polymerization rate and decreases the electrical properties to increase the loss rate of the optical fiber. There are disadvantages. On the other hand, U.S. Patent No. 4,496,713 proposes a long chain glycol copolymerization method during melt polymerization, but in this case, there is a problem of lowering strength and electrical properties by lowering excellent crystal properties of the PBT itself.

In general, there is a method of increasing the melt viscosity by introducing crosslinking and branching into the PBT molecule, but in this case, the excellent crystal properties of the PBT itself are lowered, thereby lowering the strength and electrical properties, and melting required for use in an optical fiber tube. Melt Flow Index cannot be obtained.

On the other hand, U.S. Patent No. 3,758,549 mentioned a method of mixing with a phenolic primary heat-resistant agent while suggesting a thioester-type secondary heat-resistant agent to improve thermal stability, and then stabilizers of such primary and secondary types In order to improve the stability by inducing synergy effect by using a mixture of US Patent Nos. 3,966,675 and 4,414,408, etc. are used in the US Patent No. 4,069,200 6-t-butyl-4- (dimethylaminomethyl Sterically hindered phenolic primary heat-resistant agents such as -5,6,7,8-tetrahydro-1-naphthol, 5-t-butyl-2,3-dimethyl-4-hydroxybenzylphosphonate, or The thioester type secondary heat resistant agent such as dilauryl thiodipropionate, distearyl thiodipropionate, etc. was mixed to improve the heat stability of the polyolefin resin. In addition, US Patent No. 4,185,003 discloses N, N'-hexamethylenebis (3,5-di-t-butyl-4-hydroxyhydrocinnamid), N, N'-trimethylenebis (3,5-di phenolic heat-resistant agents such as -t-butyl-4-hydroxyhydrocinamide) and bis (1,2,2,6,6-pentamethyl-4-piperidinyl) -n-butyl- (3,5 -Di-t-butyl-4-hydrobenzyl) malonate, bis- (2,2,6,6-tetramethyl-4-piperidinyl) bis (3,5-di-t-butyl-4-hydro A hindered amine such as oxybenzyl) malonate and a light stabilizer were mixed to improve the stability of the copolyetherester. In Japanese Patent Publication No. 88-40817, a method of mixing and using a compound of the 2,2,4-trimethyl-1,2-dihydroquinoline type compound and a phenothiazine type is disclosed in Japanese Patent Application No. 88-40819. A method of improving stability by mixing a mercapto compound such as 2-mercaptobenzoimidazole or 2-mercaptomethylbenzoimidazole with a 2,2,4-trimethyl-1,2-dihydroquinoline type compound is provided. I'm proposing. However, even when such a stabilizer was used, the melt flow index required by the present invention could not be obtained.

Accordingly, the present inventors, while trying to solve the problems in the conventional PBT production, during the melt polymerization, the addition of tin-based compound, siloxane-based compound and phosphorus-based compound with PBT resin and solid-phase polymerization, as a result of extrusion molding The present invention has been completed by knowing that it is possible to develop a resin for an optical fiber tube having excellent melt flowability in a predetermined range.

Accordingly, an object of the present invention is to provide a PBT resin composition having high viscosity so as to be excellent in productivity and compressibility and suitable for optical fiber coated tube applications.

Moreover, this invention also has the objective in providing the optical fiber coating tube obtained from the above resin composition.

PBT resin composition of the present invention for achieving the above object is 0.0003 to 0.01 parts by weight of the tin compound represented by the following formula (1) relative to 100 parts by weight of the polybutylene terephthalate resin composition, 0.005 siloxane compound represented by the formula (2) It is made by adding 0.01 to 2.0 parts by weight of phosphate compound represented by -0.02 parts by weight and the formula (3), characterized in that the melt flow index (Melt Flow Index) is 5-15g / 10min at a load of 2,160g, temperature 250 ℃ .

R ₁ is a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms,

R <_2> , R <_3> , R <_4> is the same or different, and is a hydrogen atom, a hydroxyl group, a C1-C10 alkyl group, an alkoxy group, or a phenyl group.

R <_5> , R <_6>, R <_7> is the same or different, and is a hydrogen atom or a C1-C10 alkyl group, n is an integer of 10-100.

R ₈ is a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms,

R ₉ is a methylene group or an ethylene group,

M is sodium, potassium or lithium.

In addition, the optical fiber coated tube obtained from the PBT resin composition is characterized in that the melt flow index (Melt Flow Index) is 5 to 15g / 10min at a load of 2160g, a temperature of 250 ℃.

The present invention will be described in more detail as follows.

With the development of the data communication industry, the use of data communication using optical fiber that is faster than the speed of copper wire is continuously expanding due to the rapid increase of users and usage of the Internet or computer communication. Therefore, it is rapidly being replaced by an optical cable network in the current copper wire.

As the coated tube forming the outer layer of the optical fiber, PBT resin having excellent electrical characteristics among general physical properties is used. However, ordinary PBT resins cannot be used for fiber optic cladding. This is because the PBT resin having a low viscosity cannot be used for optical fiber tubing because the flowability during extrusion with the optical fiber is too high to uniformly cover the optical fiber.

Therefore, high-viscosity PBT resin is preferable to be suitable for optical fiber tubing. In the present invention, a PBT resin having a load of 2,160 g and a temperature of 5 to 15 g / 10 min at a temperature of 250 ° C. has been manufactured as a condition for satisfying this.

PBT resins with high melt flow properties with a Melt Flow Index of more than 15 g / 10 min at a temperature of 250 ° C are too fast to flow (polymer flows too well) when used as an extruded product. Power supply diagram or fixed shape cannot be maintained. In particular, the tube formation of PBT resin, an outer layer polymer, does not form a uniform thickness during the extrusion of the coated tube of the optical fiber, and does not maintain the shape of the optical fiber coated tube during melt extrusion, so that an accurate extrusion molded product cannot be obtained.

On the other hand, PBT resins with a melt flow index of less than 5 g / 10 min result in high extrusion pressure when used as an extruded product, resulting in increased wear and processing temperature of the extruder, resulting in quality problems due to decomposition of PBT resins. It leads to a decrease in productivity.

PBT resin that satisfies the melt flow properties as described above is 0.003 to 0.01 parts by weight of the tin-based compound as shown in Formula 1, 0.005 to 0.02 parts by weight of the siloxane compound represented by the following formula (2) relative to 100 parts by weight of PBT resin After melt-polymerizing the composition containing 0.01-2.0 weight part of phosphorus compounds represented by 3, it is obtained by performing solid-phase polymerization with a chip-shaped product.

Formula 1

R ₁ is a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms,

R <_2> , R <_3> , R <_4> is the same or different, and is a hydrogen atom, a hydroxyl group, a C1-C10 alkyl group, an alkoxy group, or a phenyl group.

Formula 2

R <_5> , R <_6>, R <_7> is the same or different, and is a hydrogen atom or a C1-C10 alkyl group, n is an integer of 10-100.

Formula 3

R ₈ is a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms,

R ₉ is a methylene group or an ethylene group,

M is sodium, potassium or lithium.

PBT resin of the present invention by applying the siloxane-based compound represented by the formula (2) to coat the particle surface of the phosphorus-based compound such as formula 3 to increase the affinity between the polymer can be obtained an excellent melt flow effect during extrusion molding.

This is because the hydroxyl group on the right side of the siloxane compound represented by the formula (2) may be bonded to the ends of the polyester, thereby increasing the affinity between the particles and the polymer, thereby uniformly extruding the melt flow index. to be.

On the other hand, the production of a PBT resin having a general viscosity characteristics can be prepared in the same manner as a conventional polyester production method, the following examples of the production in the present invention are listed.

In the method of preparing a polyester by transesterifying a terephthalate derivative and 1,4 butanediol, and polycondensing it, 100 parts by weight of the titanium compound and PBT resin as the transesterification catalyst After the melt polymerization with a composition comprising 0.003 to 0.01 parts by weight of the tin compound, 0.005 to 0.02 parts by weight of the siloxane compound of Formula 2 and 0.01 to 2.0 parts by weight of the phosphorus compound of Formula 3, and then solid-phase polymerization of the chip-shaped product. Is carried out.

However, resins containing less than 0.0003 parts by weight of tin-based compound (Formula 1) and less than 0.01 parts by weight of phosphorus-based compound (Formula 3) in the transesterification reaction during melt polymerization had poor extrusion molding and crystallization rate during optical fiber coating. There is a problem that the solid-state polymerization speed is delayed. On the other hand, PBT resins in which tin compounds (Formula 1) were added in excess of 0.01 parts by weight were solid phase polymerized, but the b-value measured by a color meter that determines the color of the polymer chip was 15 or more. There is a problem that occurs, and when more than 2.0 parts by weight of the phosphorus-based compound (Formula 3) acts as an impurity in the resin during the melt polymerization reaction is weakened (yellowish) than the b value after the melt polymerization. In general, when used for the optical fiber tube, the b value should be 9 or less. If it exceeds 9, the color of the tube after extrusion is changed and cannot be used for the optical fiber tube.

On the other hand, the resin in which the siloxane-based compound represented by the formula (2) is less than 0.005 parts by weight, the pressure is increased during extrusion molding, bringing quality problems due to decomposition of the PBT resin due to wear of the extruder and rise in processing temperature, 0.02 If the weight part is exceeded, the effect is not increased.

PBT resin obtained through melt polymerization with the above composition is low in viscosity and unsuitable for use in optical fiber cladding tubes. Therefore, both ends of the chain of PBT resin in the high temperature vacuum solid-phase polymerization process of 190-220 ° C. to improve the viscosity. By reacting to generate a by-product butanediol or water is subjected to a process of continuously increasing the molecular weight.

The process of increasing the molecular weight starts from the surface of the PBT resin chip to both ends of the bonding process and gradually progresses to the inside according to the time.In order to proceed more rapidly, it occurs in a vacuum state by long time stay of 8 hours or more at high temperature. By-products should be removed.

The solid phase polymerization process will be described in more detail. In the solid phase polymerization reaction, a low molecular weight PBT molecule having 1,4-butanediol as a terminal is condensed to produce 1,4-butanediol as a condensation byproduct. In addition, the surrounding heat and vacuum are 1,4-butanediol to generate a 1,4-butanediol and remove the produced 1,4-butanediol from the periphery of the reaction tube to destroy the continuous chemical equilibrium to accelerate the reaction rate. In another dehydration condensation reaction, the PBT molecule at the 1,4-butanediol terminal and the PBT molecule at the carboxyl group (acid) terminal meet to form water, which is much slower than the polycondensation reaction, contributing to the increase in molecular weight. Is relatively low.

Hereinafter, the present invention will be described in detail with reference to the following Examples, which are not intended to limit the present invention.

Example 1

In the present invention, the polymer of PBT resin is 0.03 parts by weight of tetrabutyl titanate as the main catalyst and 100% by weight of PBT resin to be polymerized with 800 g of dimethyl terephthalate and 600 g of butanediol (BD), and hydrate monobutyl tin oxide as a tin compound ( hydrated monobutyltin oxide) 0.006 parts by weight of sodium 1,2'-methylene bis- (4,6-di-tert-butyl phenyl) phosphate as a phosphorus compound (Sodium 2,2'-methylene bis- (4,6-di-) tert-butyl phenyl) phosphate) 0.15 parts by weight, 0.055 parts by weight of Iganox 1010 (Shibagai Co., Ltd.) as a heat-resistant agent is subjected to a primary transesterification reaction, polydimethylsiloxane (R ₅ , R ₆ , R ₇ is CH ₃ , n is 20) 0.01 part by weight, 0.01 part by weight of lithium acetate, 0.03 part by weight of tetrabutyl titanate, and then secondarily undergoes condensation polymerization under high temperature vacuum to form a spaghetti. Discharge, cooling, cut The intrinsic viscosity of the chip shape (Ⅳ) was prepared in a PBT resin having a 0.85.

The PBT solid phase polymerization was carried out in a conventional manner in which the PBT resin prepared as described above was gradually raised from 40 ° C. to 220 ° C. and at a vacuum degree of 750 mmHg or more, with a retention condition of 20 to 25 hours.

Examples 2-3 and Comparative Examples 1-3

Only the content of monobutyltin oxide (Hydrated monobutyltin oxide) and polydimethylsiloxane was changed, and other conditions and compositions were carried out as in Table 1 in the same manner as in Example 1.

In addition, the resin obtained through the solution polymerization of Examples and Comparative Examples was subjected to the same solid-state polymerization under the same conditions as mentioned above, and then melt flowability (Melt) according to the measuring method of ASTM D-1238 at a temperature of 250 ° C. and a load of 2,160 g. Flow Index) was measured and extrusion productivity was evaluated for each product.

The results are shown in Table 1 below.

Assessment Methods

Melt flow index (Melt Flow Index) of the physical properties was measured according to ASTM D-1238 and the conditions are as follows.

― Measuring machine company and model: TINIUS OLSEN (USA), MP987 (Model)

-Temperature: 250 ℃, load 2160g

-Orifice diameter 2.0 mm

Intrinsic viscosity (IV) was measured by a Ubelod viscometer at 25 ° C. with an ortho-methphenol solution (KOLON OCP method).

Chip color b was measured using a Colormeter (Minolta CR-200, Japan).

division Melt polymerization composition (parts by weight) result A (Formula 1) B (Formula 2) C (Formula 3) Melt Flow Index (g / 10min) b value Extrusion Productivity Example One 0.006 0.010 0.15 10 6.0 Good 2 0.005 0.007 0.15 7 5.5 Good 3 0.009 0.015 0.15 13 7.0 Good Comparative example One 0.006 - 0.15 4 6.5 Bad 2 0.001 0.03 0.15 20 5.0 Bad 3 0.002 0.004 0.15 3 5 Bad 4 0.015 0.025 0.15 17 15 Bad A: Monobutyltin oxide B: Polydimethylsiloxane C: Sodium 2,2'-methylene bis- (4,6-di-tert-butyl phenyl) phosphate)

From the results of Table 1, when the melt flow index (Melt Flow Index) is more than 15g / 10min, the flowability during extrusion does not maintain the shape, and when less than 5g / 10min, the flowability is too slow, poor extrusion molding Since the molding must be carried out at a high temperature, the PBT resin may be decomposed or the wear of the device may be severe during extrusion.

As described above in detail, according to the present invention, a tin-based compound such as monobutyl tin oxide, a siloxane-based compound such as polydimethylsiloxane, and a phosphorus-based compound are added to the PBT resin as a catalyst, followed by melt polymerization. The PBT resin obtained by polymerization is highly viscous and has an extrudability enough to be applied to an optical fiber cladding tube in melt flowability, and thus can be usefully used for an optical fiber cladding tube.

Claims (2)

(Correction) 0.0003 to 0.01 parts by weight of the tin compound represented by the following formula (1), 0.005 to 0.02 parts by weight of the siloxane compound represented by the formula (2) and phosphorus represented by the formula (3) based on 100 parts by weight of the polybutylene terephthalate resin composition A polybutylene terephthalate resin for an optical fiber cladding tube made by adding 0.01 to 2.0 parts by weight of a compound and having a melt flow index of 5 to 15 g / 10 min at a load of 2,160 g and a temperature of 250 ° C. Formula 1 R ₁ is a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms, R <_2> , R <_3> , R <_4> is the same or different, and is a hydrogen atom, a hydroxyl group, a C1-C10 alkyl group, an alkoxy group, or a phenyl group. Formula 2 R <_5> , R <_6>, R <_7> is the same or different, and is a hydrogen atom or a C1-C10 alkyl group, n is an integer of 10-100. Formula 3 R ₈ is a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms, R ₉ is a methylene group or an ethylene group, M is sodium, potassium or lithium. (Correction) Phosphorus-based compounds represented by 0.0003 to 0.01 parts by weight of the tin compound represented by the following formula (1), 0.005 to 0.02 parts by weight of the siloxane compound represented by the formula (2) based on 100 parts by weight of the polybutylene terephthalate resin composition An optical fiber coating tube made of a polybutylene terephthalate resin made by adding 0.01 to 2.0 parts by weight of a compound and having a melt flow index of 5 to 15 g / 10 min at a load of 2,160 g and a temperature of 250 ° C. Formula 1 R ₁ is a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms, R <_2> , R <_3> , R <_4> is the same or different, and is a hydrogen atom, a hydroxyl group, a C1-C10 alkyl group, an alkoxy group, or a phenyl group. Formula 2 R <_5> , R <_6>, R <_7> is the same or different, and is a hydrogen atom or a C1-C10 alkyl group, n is an integer of 10-100. Formula 3 R ₈ is a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms, R ₉ is a methylene group or an ethylene group, M is sodium, potassium or lithium.