JP2015081351A - Phosphorus-containing thermoplastic polyester and phosphorus-containing heat-shrinkable tube produced from the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a phosphorus-containing thermoplastic polyester having flame retardancy suitable for production of a phosphorus-containing heat-shrinkable tube.SOLUTION: A polyester has an intrinsic viscosity of 0.70-1.10 dL/g, contains a phosphorus-containing flame retardant bonded to the molecular chain of a matrix polymer, also has a phosphorus content of 3,000-30,000 ppm, based on the weight of the polyester, and the flame retardant rating of UL94 VTM-2 and meets the requirement of the flame retardant rating of UL94 VTM-0. A method of producing a phosphorus-containing thermoplastic polyester includes a direct esterification step of reacting pure terephthalic acid(PTA) or its ester with ethylene glycol(EG) in a mol ratio (EG/PTA) of EG to PTA of 1.0-2.0 and esterifying directly and continuously in the presence of a phosphorus-containing flame retardant to be added before completion of the esterification and a polycondensation step.

Description

BACKGROUND OF THE INVENTION The present invention relates to copolyesters containing phosphorous flame retardants, and more particularly to heat shrink tubing made from such copolyesters, which are flame retardant and UL94 VTM-2 combustion. Meet the requirements of the property grade, and also meet the requirements of the UL94 VTM-0 flammability grade.

2. 2. Description of Related Art Heat shrink tubing is widely used to wrap various conductive materials for protection and insulation purposes. U.S. Pat. Nos. 3,941,752; 4,157,436; 4,940,772; 5,665,801 and 5,859,173, and Japanese Patent Some given technologies, such as 3169104 and 3329410, have proposed several polyesters containing flame retardants, these existing materials being flame retardant polyester fibers, fabrics, films and It has been widely used to manufacture circuit boards. However, none of the flame retardant heat shrink tubes are used in the market.

US Pat. No. 3,941,752 US Pat. No. 4,157,436 US Pat. No. 4,940,772 US Pat. No. 5,665,801 US Pat. No. 5,859,173 Japanese Patent No. 3169104 Japanese Patent No. 3329410

  Due to the prohibition of PVC, heat shrink tubing for use in electrical insulation is no longer manufactured with PVC. As an alternative, several related polyesters disclosed in a given prior art have been used favorably to produce heat shrink tubing, but none of the given prior art has ever been flame retardant. No mention is made of using a polyester containing flame retardant to produce heat-shrinkable tubes with properties.

  Thus, the main object of the present invention is to disclose the flame retardant effect of a thermoplastic polyester having an intrinsic viscosity of 0.70 to 1.10 dL / g, the disclosed polyester comprising a phosphorus-containing flame retardant. It is obtained by bonding to the matrix polymer's own molecular chain during the process of changing the molecular structure of the matrix polymer.

  The disclosed polyester is suitable for the production of phosphorus-containing heat-shrinkable tubes having an elemental phosphorus content between 3,000 and 30,000 ppm of the polyester weight and having permanently flame retardant properties. The resulting phosphorus-containing heat shrink tubing has a UL94 VTM-2 flame retardant rating and further meets the requirements of UL94 VTM-0 flame retardant rating.

  The disclosed polyester further comprises between 0.005 and 0.5 wt% inorganic particles based on the weight of the polyester, the inorganic particles having a particle size between 0.1 and 0.5 μm being titanium oxide, Selected from barium sulfate, calcium carbonate or silicon dioxide.

  Another main object of the present invention is to provide a flame-retardant and heat-shrinkable phosphorus-containing heat-shrinkable tube. The heat-shrinkable tube is made of only a thermoplastic polyester incorporating a flame retardant containing elemental phosphorus, or a mixture of a thermoplastic polyester with a phosphorus-containing flame retardant and a thermoplastic polyester that does not contain any flame retardant. Either manufactured. The tube has a phosphorus element content between 3,000 and 12,000 ppm based on its weight. When used to wrap an article, the tube provides flame resistance and insulation to the article it wraps.

  Flame-retardant and heat-shrinkable phosphorus-containing heat-shrink tubes have a longitudinal shrinkage between 5% and 15% and a lateral shrinkage greater than 35% when exposed to boiling water.

  Phosphorus-containing heat-shrinkable tubes, when heat-shrinking articles, are wrinkled, raised, exposed to a temperature of 180 ° C. for 30 minutes, or exposed to a temperature of 105 ° C. for 180 minutes (or 3 hours). Maintain full wrapping without sagging, flaking off, cracking and warping.

  The phosphorus-containing heat shrink tubing has a UL94 VTM-2 flame retardant rating and further meets the requirements of UL94 VTM-0 flame retardant rating. Accordingly, the phosphorus-containing heat-shrinkable tube is suitable for wrapping various conductors and / or electronic devices, and can provide flame resistance and insulation for the wrapped conductors and / or electronic devices.

  The thermoplastic polyester of the present invention produced by bonding a phosphorus-containing flame retardant to a molecular chain of a matrix polymer is essentially a copolyester polymer (hereinafter referred to as phosphorus-containing thermoplastic polyester) that has undergone a change in the molecular structure of the matrix. Called). The disclosed thermoplastic polyesters are permanently flame retardant and are suitable for producing flame retardant heat shrink tubing. The disclosed heat shrink tubing, when used to wrap electronic equipment, provides flame resistance and insulation to the wrapped article.

  The disclosed phosphorus-containing thermoplastic polyesters are made from diacid, diol and phosphorus-containing flame retardant components via conventional processes for synthesizing polyesters. For example, the disclosed phosphorus-containing thermoplastic polyester may be synthesized using a PTA manufacturing process or a DMT manufacturing process. In this case, the phosphorus-containing flame retardant is added at any point prior to the end of the esterification of the diacid and diol, or added directly into the diacid and diol plasma.

  The diacid is primarily pure terephthalic acid (PTA) or an ester thereof, and an additional second component such as, for example, isophthalic acid, 2,6-naphthalenedicarboxylic acid, or esters thereof may be added. However, these second components are not essential and, when used, together form a portion of less than 15 mol% in the copolyester.

  The diol is mainly ethylene glycol (EG), for example, diethylene glycol, 1,4-cyclohexanedimethanol, propylene glycol, 2,2-dimethyl-1,3-propylene glycol (NPG), 2-ethyl-2- Additional second diols such as those selected from the group consisting of butyl-1,3-propylene glycol (BEPG) and butanediol may be added. However, these second diols are not essential and, when used, together form less than 15 mole percent of the copolyester. Otherwise, the resulting phosphorus-containing thermoplastic polyester may be in an amorphous state and tend to have aggregation during solid phase polycondensation, making it difficult to increase the intrinsic viscosity of the phosphorus-containing thermoplastic polyester It becomes.

  The phosphorus-containing flame retardant is a phosphorus-containing material selected from those having chemical structural formulas of (I), (II), (III), (IV), (V), (VI), (VII) and (VIII) It can be a combination of one or more compounds, preferably those having the chemical structural formula (I), (II), (III) or (IV).

  In the formula, n is a positive integer.

  The disclosed phosphorus-containing thermoplastic polyester has a phosphorus content between 3,000 and 30,000 ppm based on the weight of the polyester. When the phosphorus-containing thermoplastic polyester has a phosphorus content of less than 3,000 ppm, the resulting heat shrink tubing does not meet the requirements of UL94 VTM-2 flame retardant grade. On the other hand, when the phosphorus content is greater than 30,000 ppm, it is difficult for the polyester to have its intrinsic viscosity reaching a range between 0.70 to 1.10 dL / g, and an intrinsically low intrinsic viscosity is There is a risk of making the polyester more unstable during the tube blow molding process and can result in significant thickness variations in the manufactured heat shrink tubing.

  The disclosed phosphorus-containing thermoplastic polyester is between 0.70 and 1.10 dL / g, preferably between 0.80 and 1.00 dL / g, most preferably between 0.80 and 0.90 dL / g. Has its intrinsic viscosity. When using either a PTA manufacturing process or a DMT manufacturing process to synthesize polyester, it is possible to increase the intrinsic viscosity directly in the range of 0.70 to 1.10 dL / d during the melt polymerization process. is there. Alternatively, it is possible to increase the intrinsic viscosity in the range between 0.70 to 1.10 dL / d during the solid state polymerization process. When the phosphorus-containing thermoplastic polyester has an intrinsic viscosity of less than 0.70 dL / g, heat shrink tubing made by melting and extruding the polyester tends to have an inconsistent thickness. On the other hand, if the intrinsic viscosity is higher than 1.10 dL / g in the process of melting and extruding polyester for producing a heat-shrinkable tube, the material injection tends to be hindered, and the process of extruding the heat-shrinkable tube and blowing the tube Add difficulty.

  The following description relates to an example where a PTA manufacturing process is performed to produce the disclosed phosphorus-containing thermoplastic polyester. The process includes the following steps.

1. Adding a phosphorus-containing flame retardant to a batch of plasma blended with pure terephthalic acid (PTA) and ethylene glycol (EG);
Here, the molar ratio of EG / PTA is between 1.0 and 2.0.

2. Continuously pumping plasma into the esterification reactor to perform the first direct esterification.
Here, ethylene glycol and the water produced during the direct esterification are separated by induction through an evaporation tube into a distillation column, and the ethylene glycol collected at the bottom of the distillation column is led back to the esterification reactor.
Here, the material temperature for esterification is between 240 and 270 ° C., preferably between 250 and 260 ° C., and the esterification pressure is between normal pressure and 2.0 Kg / cm ² , preferably 0.01 to is between 1.0 kg / cm ^2, the esterification time is between 3 to 8 hours, preferably between 4-6 hours, and the conversion of monomer at the outlet of the esterification reactor, at least 92 %, Preferably higher than 95%.

3. Performing a second polycondensation.
Here, the monomer produced | generated by the above-mentioned esterification is pumped to a prepolymerization tank for prepolymerization.
Here, the material temperature for prepolymerization is between 260-280 ° C, preferably between 250-260 ° C, the prepolymerization pressure is between 10-200 mmHg, and the prepolymerization time is 0.5-2. The pre-polymerization gaseous by-product such as ethylene glycol is vacuum pumped to a cooler to cool to liquid.

4). The step of continuously feeding the oligomer produced by the above-mentioned prepolymerization to a high vacuum finisher to perform further polycondensation.
Therefore, the intrinsic viscosity increases to 0.50 dl / g or more, more preferably 0.60 dl / g or more, and most preferably 0.70 dl / g or more.
Here, the material temperature in the finisher is between 265-290 ° C., preferably lower than 285 ° C., and the vacuum pressure in the finisher is lower than 2 mmHg.

  5. Continuously pumping the polymer produced at the finisher to a die head where it is extruded as a rod, then quickly cooling it with cold water and then cutting it into particles of the disclosed phosphorus-containing thermoplastic polyester by means of a particle cutter .

  The following description relates to an example where a DMT manufacturing process is performed to produce the disclosed phosphorus-containing thermoplastic polyester. The process includes the following steps.

1. Performing a transesterification reaction with a diol using an ester of a diacid as a material, and adding a transesterification catalyst such as manganese acetate before starting the reaction.
Here, the methanol produced | generated by transesterification is isolate | separated with a distillation tower, and is not introduce | transduced into a transesterification tank.

  2. Adding a phosphorus-containing flame retardant at any point before the end of esterification;

  3. When the amount of methanol produced reaches a theoretical capacity of 98%, a catalyst selected from an antimony catalyst, a germanium catalyst, a titanium catalyst, and any combination thereof is added to perform polymerization in a vacuum environment, and When the polyester reaches a viscosity greater than 0.7 dL / g, immediately take the copolyester out of the polymerization process, quickly cool it and cut it into phosphorus-containing thermoplastic polyester (particles).

  An alternative method for producing the disclosed phosphorus-containing thermoplastic polyester is to first perform a melt blend on the phosphorus-containing flame retardant and the phosphorus-free thermoplastic polyester, and perform a solid state polymerization on the blend, Thereby, a phosphorus-containing thermoplastic polyester having an intrinsic viscosity between 0.70 and 1.10 dL / g is obtained.

  The disclosed phosphorus-containing thermoplastic polyesters further comprise between 0.005 and 1.0% by weight, preferably between 0.005 and 0.5% by weight, most preferably between 0.01 and 0.5%, based on the weight of the polyester. Contains between 0.5% by weight of inorganic particles. The inorganic particles are after the end of the esterification reaction but must be added into the reactor before the start of the polymerization.

  The inorganic particles are selected from titanium oxide, barium sulfate, calcium carbonate or silicon dioxide having a particle size of less than 1 μm, preferably between 0.1 and 0.5 μm.

  The inorganic particles and the phosphorus-free thermoplastic polyester can cooperate to form a masterbatch, which is then subjected to a melt blending process with a phosphorus-containing flame retardant to form the disclosed phosphorus-containing thermoplastic polyester.

  The heat shrink tubing of the present invention is manufactured from the disclosed phosphorus-containing thermoplastic polyester. Based on the weight of the heat shrink tube, it has a phosphorus content between 3,000 and 12,000 ppm, and it is a flame retardant heat shrink tube (hereinafter referred to as phosphorus containing heat shrink tube). is there.

  The disclosed phosphorus-containing heat shrink tubing has a thickness between 20-200 μm and an outer circumference between 4-300 mm and has a UL94 VTM-2 flame retardant rating, and further UL94 VTM-0 flame retardant Meet sex grade requirements.

  The disclosed phosphorus-containing heat-shrinkable tube, when made from a phosphorus-containing thermoplastic polyester incorporating inorganic particles, prevents melt dripping during combustion and meets the requirements of UL94 VTM-0 flame retardant grade Can have.

  The disclosed phosphorus-containing heat-shrinkable tube is manufactured by the following steps.

  1. The disclosed phosphorus-containing thermoplastic polyester alone, or a mixture of the disclosed phosphorus-containing thermoplastic polyester and phosphorus-free thermoplastic polyester in a weight ratio of 10 to 40:60 to 90 (hereinafter collectively referred to as phosphorus-containing thermoplastic polyester and The phosphorus-containing thermoplastic polyester is dried with dehumidified air at 150 to 170 ° C. for 4 to 6 hours.

  2. Melting the phosphorus-containing thermoplastic polyester into a gel at a temperature between 250-270 ° C. and extruding the phosphorus-containing thermoplastic polyester gel into an unstretched hollow tube preform using an extruder having a ring-shaped die .

3. Immediately cool the preform through a cooling bath, and pass the preform between a series of feed rollers at a rotational speed set to 100 rpm and carry the preform to a hot water bath or infrared lamp heating device where the preform is transferred. The reforming is heated to a temperature above its glass transition temperature, and then having the diameter of the preform expanded 1.3 times or more by introducing compressed air and blow-molding the preform.
Here, the temperature of the tube blow molding process is preferably between 85 ° C and 105 ° C.

  4. Winding the expansion tube around a series of nip rollers at a rotational speed set at 105 rpm to obtain the disclosed phosphorus-containing heat shrink tube.

  The unstretched hollow tube preform of the disclosed phosphorus-containing heat shrink tubing is expanded in the transverse direction (TD) during the tube blow molding process and in the machine direction (MD) as it passes through the feed and nip rollers. Expanded twice. As a result, the disclosed phosphorus-containing heat shrink tubing has a machine direction (MD) stretch ratio equal to the ratio between the stretch tube stretch rate and the preform feed rate, and the expanded tube diameter and preform It has a transverse direction (TD) stretch ratio equal to the ratio between diameters.

  The disclosed phosphorus-containing heat shrink tubing preferably has its machine direction (MD) stretch ratio between 1.0 and 3.0 and its transverse direction (TD) stretch ratio between 1.3 and 4.5. Have.

  The disclosed phosphorus-containing heat shrink tubing is cooled immediately after MD and TD elongation and is heat shrinkable. In other words, when heat is applied, the heat shrink tube shrinks in both the transverse direction (TD) and the longitudinal direction (MD). Thus, when the disclosed phosphorus-containing heat shrink tube is attached around the article and then heated, it undergoes TD shrinkage and MD shrinkage, and the article is closely wrapped.

  The disclosed phosphorus-containing heat-shrinkable tube further has the following characteristics.

1. Phosphorus-containing heat shrink tubing exhibits an MD heat shrinkage between 5% and 15% and a TD heat shrinkage greater than 35% after being placed in boiling water at 100 ° C. for 30 seconds.
If the MD heat shrinkage is less than 5%, the phosphorus-containing heat shrink tube cannot wrap the article closely. If the MD heat shrinkage is greater than 15%, the phosphorus-containing heat shrink tube can deform and move as it wraps the article. If the amount of TD heat shrinkage is less than 35%, the heat shrink tube packaging may not be tightly packed.

  2. Phosphorus-containing heat-shrinkable tubes are used to wrap and shrink defective articles after exposure to 180 ° C for 30 minutes or after exposure to 105 ° C for 180 minutes. Maintains full wrapping without dropping, cracking or warping.

  3. Since the phosphorus-containing heat-shrinkable tube can be applied to enclose an aluminum capacitor, a lithium battery, and a motor coil, it can impart flame retardancy and insulation to the encapsulated aluminum capacitor, lithium battery, and motor coil.

  4). Phosphorus-containing heat shrink tubing, when containing inorganic particles, can relax better after being rolled up.

  5. The pattern-printed phosphorus-containing heat-shrink tube keeps the pattern clear and sharp even after being washed with acetone.

  An alternative method for producing the disclosed phosphorus-containing heat shrink tubing is accomplished using a double bubble tubular film extrusion process.

  Some examples and comparative examples are provided below to further demonstrate the physical properties and characteristics of the disclosed heat shrink tubing.

1. The flame retardant rating test is performed according to UL94-VTM thin material vertical burning test.

2. Stability test during tube blow molding Observe if the heat shrink tube has a consistent thickness.

3. Packaging appearance test When the heat-shrinkable tube containing phosphorus is heat shrunk to wrap the article, it is exposed to a temperature of 180 ° C. for 30 minutes or after being placed in an oven to be exposed to a temperature of 105 ° C. for 180 minutes. Observe whether it remains perfectly conformed to the surface of the article without sagging, flaking off, cracking and warping.

[Pre-formed “phosphorus-free polyester particles”]
Sample PET-A polyester particles: copolyester containing about 2.5 mol% IPA Sample PET-C polyester particles: copolyester containing about 10 mol% IPA

  [Pre-formed “phosphorus-containing polyester particles”]

< PET-F1 polyester particles>: Using flame retardant (I) 10.81 parts by weight of bis-hydroxyethyl terephthalate monomer (hereinafter abbreviated as BHET), 0.4478 parts by weight of flame retardant (I) (ie, propion) The acid 3- (hydroxyphenylphosphinyl)) and 3.243 parts by weight of ethylene glycol (EG) are weighed and then these materials are placed in a reactor to carry out a melt polymerization process reaction.

  A batch of phosphorus-containing polyester particles having a phosphorus content of 6,000 ppm and an intrinsic viscosity at 0.65 dL / g melt polycondensation was synthesized according to the process described above for producing the disclosed phosphorus-containing thermoplastic polyester. After solid state polymerization, the resulting PET-F1 polyester particles have its intrinsic viscosity of 0.80 dL / g.

< PET-F2 polyester particles>: Using flame retardant (II) 10.81 parts by weight of BHET, 0.522 parts by weight of flame retardant (II) (ie, oxaphospholane glycol ester) and 3.243 parts by weight Ethylene glycol (EG) is weighed and then these materials are placed in a reactor to carry out a melt polymerization process reaction.

  A batch of phosphorus-containing polyester particles having a phosphorus content of 6,000 ppm and an intrinsic viscosity at 0.65 dL / g melt polycondensation was synthesized according to the process described above for producing the disclosed phosphorus-containing thermoplastic polyester. After solid state polymerization, the resulting PET-F2 polyester particles have its intrinsic viscosity of 1.10 dL / g.

< PET-F3 polyester particles>: Using flame retardant (III) 10.81 parts by weight of BHET, 0.84 parts by weight of flame retardant (III) (ie, oxalic acid, bis (2-hydroxyethyl) (6H- Dibenz [c, e] [1,2] oxaphosphorin-6-ylmethyl) ester) and 3.243 parts by weight of ethylene glycol (EG), and then these materials are placed in a reactor and melt polymerized. Perform the process reaction.

  A batch of phosphorus-containing polyester particles having a phosphorus content of 6,000 ppm and an intrinsic viscosity at 0.65 dL / g melt polycondensation was synthesized according to the process described above for producing the disclosed phosphorus-containing thermoplastic polyester. After solid state polymerization, the PET-F3 polyester particles have its intrinsic viscosity of 0.9 dL / g.

< PET-F4 polyester particles>: Using flame retardant (IV) 10.81 parts by weight of BHET, 0.8695 parts by weight of flame retardant (IV) (ie, 2- (9,10-dihydro-9-oxa-) 10-phosphaphenanthrene-10-oxide) -1,4-bis (2-hydroxyethoxy) phenylene ester) and 3.243 parts by weight of ethylene glycol (EG), and then these materials are added to the reactor. To carry out the melt polymerization process reaction.

  A batch of phosphorus-containing polyester particles having a phosphorus content of 6,000 ppm and an intrinsic viscosity at 0.65 dL / g melt polycondensation was synthesized according to the process described above for producing the disclosed phosphorus-containing thermoplastic polyester. After solid state polymerization, the PET-F4 polyester particles have its intrinsic viscosity of 0.9 dL / g.

< PET-F5 polyester particles>: Using flame retardant (I) The obtained PET-F5 polyester particles have a phosphorus content of 30,000 ppm and an intrinsic viscosity in melt polycondensation of 0.60 dL / g. And manufactured by the same synthesis process as that of PET-F1 polyester. After solid state polymerization, the PET-F5 polyester particles have its intrinsic viscosity of 0.80 dL / g.

< PET-F6 polyester particles>: Using flame retardant (I) The obtained PET-F6 polyester particles have a 6,000 ppm phosphorus content, a 3,000 ppm calcium carbonate content, and a 0.65 dL / g melt polycondensation. In addition to having an intrinsic viscosity at, it is produced by the same synthetic process as that for the production of PET-F1 polyester. After solid state polymerization, the PET-F6 polyester particles have its intrinsic viscosity of 0.8 dL / g.

< PET-F7 polyester particles>: Using flame retardant (I) Using a twin screw extruder, PET-A polyester particles and flame retardant (I) are melted and blended, and then the disclosed phosphorus-containing thermoplastic polyester It is produced by synthesizing phosphorus-containing polyester particles containing 6,000 ppm of phosphorus using a process for producing. After solid state polymerization, the PET-F7 polyester particles have its intrinsic viscosity of 0.8 dL / g.

  A heat shrink tube was made from PET-F1 polyester particles. Table 1 shows the prescription and test results of the polyester particles.

  A heat shrink tube was made from PET-F2 polyester particles. Table 1 shows the prescription and test results of the polyester particles.

  A heat shrink tube was made from PET-F3 polyester particles. Table 1 shows the prescription and test results of the polyester particles.

  A heat shrink tube was made from PET-F4 polyester particles. Table 1 shows the prescription and test results of the polyester particles.

  A heat shrink tube was made from PET-A polyester particles and PET-F5 polyester particles premixed at a weight ratio of 60:40. Table 1 shows the prescription and test results of the polyester particles.

  A heat shrink tube was made from PET-A polyester particles and PET-F5 polyester particles premixed at a weight ratio of 80:20. Table 1 shows the prescription and test results of the polyester particles.

  A heat shrink tube was made from PET-A polyester particles and PET-F5 polyester particles premixed at a weight ratio of 90:10. Table 1 shows the prescription and test results of the polyester particles.

  A heat shrink tube was made from PET-F6 polyester particles. Table 1 shows the prescription and test results of the polyester particles.

  A heat shrink tube was made from PET-F7 polyester particles. Table 1 shows the prescription and test results of the polyester particles.

(Comparative Example 1)
A heat shrink tube was made from PET-C polyester particles. Table 1 shows the prescription and test results of the polyester particles.

(Comparative Example 2)
A heat shrink tube was made from PET-C polyester particles and PET-F5 polyester particles premixed at a weight ratio of 92: 8. Table 1 shows the prescription and test results of the polyester particles.

(Comparative Example 3)
A heat-shrinkable tube was made from PET-F1 polyester particles, followed by solid phase polymerization (IV = 0.65 dL / g). Table 1 shows the prescription and test results of the polyester particles.

Note:
1. PET-A contains 2.5 mol% IPA; IV = 0.72 dl / g;
2. PET-C contains 10 mol% IPA; IV = 0.85 dl / g;
3. PET-F1 uses flame retardant (I) and contains a phosphorus content of 6,000 ppm; IV = 0.80 dl / g;
4). PET-F2 uses flame retardant (II) and contains a phosphorus content of 6,000 ppm; IV = 1.10 dl / g;
5. PET-F3 uses flame retardant (III) and contains a phosphorus content of 6,000 ppm; IV = 0.90 dl / g;
6). PET-F4 uses flame retardant (IV) and contains a phosphorus content of 6,000 ppm; IV = 0.90 dl / g;
7). PET-F5 uses flame retardant (I) and contains a phosphorus content of 30,000 ppm; IV = 0.80 dl / g;
8). PET-F6 uses flame retardant (I) and contains a phosphorus content of 6,000 ppm and a calcium carbonate content of 3,000 ppm; IV = 0.80 dl / g;
9. PET-F7 is made using a twin screw extruder, uses flame retardant (I) and contains a phosphorus content of 6,000 ppm; IV = 0.80 dl / g.

Result :
According to Table 1, the phosphorus-containing heat-shrinkable tubes made of the polyesters of Examples 1-9 are flame-retardant and heat-shrinkable and have a flame-retardant performance that satisfies at least the requirements of UL94 VTM-0 flame-retardant grade. It is recognized that In addition, all of the obtained phosphorus-containing heat-shrinkable tubes exhibited packaging integrity after being heated at 180 ° C. for 30 minutes and after being heated at 105 ° C. for 3 hours, and thus meet the industrial standards.

Claims (7)

A phosphorus-containing thermoplastic polyester used in the manufacture of a phosphorus-containing heat-shrinkable tube having a UL94 VTM-2 flame retardant rating, the polyester having an intrinsic viscosity between 0.70 and 1.10 dL / g; A phosphorus content of between 3,000 and 30,000 ppm based on the weight of the polyester, pure terephthalic acid (PTA) or its ester in ethylene glycol (EG) and the molar ratio of the EG to the PTA (EG / PTA) is reacted in the range of 1.0 to 2.0, and continuously in the presence of a phosphorus-containing flame retardant added before the end of esterification, direct direct esterification step and polycondensation The phosphorus-containing flame retardant obtained through the steps is the following (I), (II), (III), (IV), (V), (VI), (VII) or (VIII) Chemical structure A phosphorus-containing thermoplastic polyester, characterized in that it is a combination of one or more phosphorus-containing compounds selected from those having a formula.

  2. The polyester according to claim 1, wherein the polyester further comprises between 0.005 and 0.5% by weight of inorganic particles, based on the weight of the polyester, between 0.1 and 0.5 [mu] m. The polyester according to claim 1, wherein the inorganic particles having a particle size of: are selected from titanium oxide, barium sulfate, calcium carbonate, or silicon dioxide.   The polyester according to claim 1 or 2, wherein the polyester has an intrinsic viscosity of 0.80 to 1.00 dL / g.   A phosphorus-containing heat-shrinkable tube made from the phosphorus-containing thermoplastic polyester of claim 1, having a phosphorus content between 3,000 and 12,000 ppm based on the weight of the heat-shrinkable tube. Having a longitudinal shrinkage between 5% and 15% and a lateral shrinkage greater than 35% when exposed to boiling water, and having a UL94 VTM-2 flame retardant rating. A heat-shrinkable tube containing phosphorus.   The phosphorus-containing heat-shrinkable tube according to claim 4, wherein the phosphorus-containing heat-shrinkable tube heat-shrinks the article and is then heated at a temperature of 180 ° C for 30 minutes or at 105 ° C for 3 hours. A phosphorus-containing heat-shrinkable tube, characterized in that it still maintains a complete coating without wrinkles, bumps, sagging, flaking off, cracking and warping.   A phosphorus-containing heat-shrinkable tube made from the phosphorus-containing thermoplastic polyester of claim 2, wherein the phosphorus content is between 3,000 and 12,000 ppm based on the weight of the heat-shrinkable tube and 0. Containing between 0.1 and 0.5% by weight of said inorganic particles and having a longitudinal shrinkage of between 5% and 15% and a lateral shrinkage of greater than 35% when exposed to boiling water. And a phosphorus-containing heat-shrinkable tube, characterized by having a UL94 VTM-0 flame retardant rating.   The phosphorus-containing heat-shrinkable tube according to claim 6, wherein the phosphorus-containing heat-shrinkable tube heat-shrinks and wraps the article and is then heated at a temperature of 180 ° C for 30 minutes or at 105 ° C for 3 hours. A phosphorus-containing heat-shrinkable tube, characterized in that it still maintains a complete coating without wrinkles, bumps, sagging, flaking off, cracking and warping.